• 6.1 What original pieces are interchangable between the various H-bodies?
• 6.2 What are some popular replacement body parts?
• 6.3 What are some specs for the Spyder decals?
• 6.4 Where can I find functional front and rear spoilers?
• 6.5 How much do the H-bodies weigh?
• 6.6 What are the exterior dimensions of the H-bodies?
• 6.7 What is the Coefficient of Drag for H-bodies?
• 6.8 How do I stiffen up the body? (subframe connectors)
• 6.9 What are particularly bad areas for rust?
• 6.10 Where can I get replacement Torx screws for the headlight bezels?
• 6.11 Where can I get replacement door seals?
• 6.12 Where is that #@$# squeak coming from?
• 6.13 What do I need to convert a 2-headlight Monza to a 4-headlight front end?
• 6.14 Were 4-headlight front ends only available on hatchback Monzas, and 2-headlights only available on coupes?
• 6.15 What can I do about the anodized aluminum trim and clips?
• 6.16 How do I install a back-half chassis kit?
• 6.17 Where can I get a roll bar or roll cage?
• 6.18 Where can I get replacement hatch struts?
• 6.19 How do I install an aftermarket racing front subframe?
• 6.20 Where can I get a driveshaft loop for a torque-arm car?
• 6.21 How do I fix my sagging/mis-aligned doors?
• 6.22 How do I convert my '74-'77 Vega front end to the '71-'73 style?
• 6.23 How do Mirage panels attach to the Monza?
• 6.24 How do I convert a Vega Wagon to a Panel Express?
• 6.25 How do I remove the fixed rear windows?
• 6.26 What should I know about the cowl seal?
• 6.27 What are likely sources of a water leak?
• 6.28 What other brands of cars can supply body accessories?

For Monza Ken (mahoy78spyder) says:

• All years fenders 75-80 interchange (doesn't matter if notch or hatch).
• All hatchback doors interchange with other hatchbacks 75-80.
• All notchback doors interchange with other notchbacks 75-80 (but some trim swapping may have to take place).
• Doors on notchback and hatchback different.
• Windshields between notchback and hatchback don't interchange either.
• The only exception to ALL of the rules above is the '78 Monza S and Monza Wagon (Vega body with Monza front end).

For Vega:

• Early-model to late-model front end: all pieces forward of the firewall must be changed.
• Doors interchange for all years, but only for like-bodies (wagon-wagon, hatch-hatch, etc., but wagon-hatch won't work).

• Motion's L88 (Corvette-style) Vega hood
• Chevrolet parts to convert a Monza into a replica Trans Am car:

        Front Fender Extension R.H        3965779
        Front Fender Extension L.H.       3965780
        Rear Fender & door extension R.H. 3965791
        Rear Fender & door extension L.H. 3965792
        Front Air Dam and Grill           3965793
        Rear Spoiler end cap R.H.         3965794
        Rear Spoiler end cap L.H.         3965795
        Rear spoiler center               3965796
        Hood                              3965797
        Rear Deck Lid                     3965798
    

Spyder decal part numbers: Hood 20052964, Left Door 3063003, Right Door 3063002, Rear spoiler 356598 for these colors:
1977: Lt Blue Met #22, Dk Aqua #38, Med Green Met #44, Camel Tan Met #63
1978: Lt Blue Met #22, Ultramarine #24, Med Green Met #44, Camel Tan Met #63

Take a rear spoiler from a 2nd-gen Camaro ('70-'81). Once the center section is narrowed, the spoiler will fit well and look good.

Vega:

• 1971-1972: 2146 to 2333 lbs (sedans are lightest, wagons are heaviest)
• 1973-1974: 2219 to 2404 lbs (new bumpers)
• 1975-1977: 2415 to 2571 lbs (more smog equipment, general bloat)

Monza:

• The Monza varied from 2700-3000 lbs depending on options. All Monza-based models came out after the "big bumper" regulations and emissions regulations, so the weight doesn't increase much over the prodution run from 1975-1980.
• To give you some idea of how options add up, here is some information from the 1978 GM Dealer's Guide (in pounds):

      Curb weight - full gas & fluids w/4 cylinder engine:
        1HM27 2-dr notchback coupe  2726
        1HM07 2-dr hatchback coupe  2782
        1HM77 2-dr hatchback coupe  2695
        1HM15 2-dr station wagon    2754
        1HR27 2-dr notchback coupe  2781
        1HR07 2-dr hatchback coupe  2823
  
      Add the following weights for these options:
        A/C L4 Engine                 60
        V6 Engine                     61
        V8 Engine                     85
        Floor Mats                     6
        Power Brakes                   8
        Power Steering                34
        Stereo w/Tape Player          11
        Wheel Trim Rings               6
        3.2 liter L6                  71
           w/3spd auto trn            12
        3.8 liter V6                  70
           w/3spd auto trn            12
        5.0 liter v8                 275
           w/3spd auto trn            10
        LX6 engine                     0
           w/3spd auto trn            19
           w/5spd tran               -16
      

Data for 1976 models, other similar:

• All models wheelbase: 97"
• All models width: 65.4"
• All models front tread width: 54.8"
• All models rear tread width: 53.6"

• Vega length: 175.4" (170" 1971-1972, 173" 1973)
• Vega coupe/wagon height: 51.8"
• Vega hatch height: 50.0"

• Monza coupe length: 177.8"
• Monza coupe height: 49.8"

• Monza hatch length: 179.3"
• Monza hatch height: 50.2"

  Vega Hatchback:  0.40
  Monza Hatchback: 0.40
  Monza Coupe:     0.42
  Monza IMSA:      around 0.30

Try adding subframe connectors, which connect the front and rear subframes giving you the stiffness of a full-frame car. Note that some aftermarket pieces require cutting the rear footwells-- Alston Chassisworks subframes, for example (regardless, these connectors get good reviews from club members and are reasonably priced).

Roll bars and cages also help, plus provide extra safety. See 6.17.

On the Vega, check the rear quarter panel drains. If clogged, the interior of the panel will stay wet and rust. Enlarge them if needed.

Robert (twelve_second_vega) adds:
"I see a lot of rust around the windshield and hatches on Vegas. I discovered that I can drill holes in the window channel area and let water drain into the cowling, preventing rust formation. The rear hatch's glass channel can be drilled on early cars, but I am not sure about later models. Be sure to treat the drilled area before reassembly! With the windshield out of the car, you drill a hole into the bottom of the glass channel at each corner, about a 1/4" hole is good. This will open into the interior of the car. Next, from under the dash, drill another hole through the inner firewall and into the cowl cavity in front of the windshield. I then epoxied 2 nylon tubes into these holes that carry the water out of the channel and allows it to drain into the cowling. It may be overkill in one respect, but it keeps water from standing in the channel."

Dan (dancv32) writes:
"I will always go over a restored/repainted car very carefully. Why was so much restoration needed on a car with that kind of mileage? Take a magnet to check for body fillers. Check gap between 1/4 panel and door edge to make sure the gaps are correct. Usually a 1/4 panel replacement will change the gaps based on cars I have personnally observed with replacement 1/4 panels. Rust is a problem in the following areas. Inside spare tire well, underside of hatch at lip and around window. Sometimes if moisture or corrosion is present around the windshield, it will also be present on the surface of the dash. Underside of hood at seams. Shake hood and listen for rust particles moving around. Check battery tray, underneath battery tray and around core supports for corrosion. Check mounting points for trailing arms at the rear suspension. Check lower inside edges of rear 1/4 panel. Check carefully around the lower gasket of the 1/4 windows. I have seen rust occasionally show up on the metal rail above the rear 1/4 interior plastic panels. Check battery side frame rail around the stabilizer bar mount, bumper bracket mount, idler arm mount and top of the frame rail below the battery. If extensive rust is present inside the frame rail it will sometimes appear at the exterior at these locations. I personnally look for a great body and interior. It is a labor intensive effort to repair,prep and paint a car if you do it the correct way."

Body Tite part #45860, any major auto parts store.

For Monza:

• Metro Moulding sells these:
  78-79 hatchback seal #LP 46-C (might fit others?)
  door seal (???) #LM 12-K
  75-80 Door seal (hatchback) #LM 13-M
  75-80 Door seal (coupe) #LM 13-N
• JC Whitney sells these:
  Window channel (window slides inside it) part #18ZX4878N (need to mitre edges)
  Window glass belt weatherstrip part #81ZX9747R (need 2 each side)
  Hatchback weatherstrip part #14ZX3539Y
• Soff Seal sells these:
  door seal part #829 ???
  door weatherstrip part #8028
  

For Vega:

• Metro Moulding sells these:
  71-77 Rear Swing Out Quarter Seals #WR 2010-R
  71-77 Hatchback seal #L46-C
  71-77 Rear Quarter Window Seal #LP 59-G
  71-77 Door seal (hatchback) #LM 13
  71-77 Door seal (coupe and wagon) #LM 13-A
• J.C. Whitney sells these:
  71-77 window belt weatherstrip part #55XJ4077Y
  wagon liftgate (also hatch/trunk?) part #81XJ3493W
• Supercar Specialty (part #???)

Also check the vendor section; other vendors still sell these and other pieces.

• Swaybar bushing--lubricate or replace
• Rubber hood stops--lubricate or replace

• 4-headlight fascia (2 part)
• front bumper
• matching hood
• radiator support

If you want to put a Monza front end on your Vega or vice-versa, Key (mahoy78spyder) writes: "Basically, you've got really only one way to do this and that is to use an entire dog-house from a Monza w/ the Sport front end (4 headlight). You will need the fenders, header panel assembly, front radiator support, and hood. Those alone will be tough to line up and bolt on precisely. But the toughest part of it all is getting a rear-hinged hood to bolt onto a car that was originally a front-hinged vehicle. You can't really take the cowl of a Monza and transplant to your Vega (not without compromising structural integrity) to enable a "bolt-on" solution for your hood."

Nope! There were Spyder Coupe (4-headlight front end) and Sport hatchback (2-headlight front end) models available.

If you don't care about having an original finish, buff off the anodizing and polish the aluminum. Then clearcoat it. Otherwise, you'll need to have the trim reanodized. Places that perform this service can be found in Hemmings Motor News (see any bookstore's magazine rack). Or check with Eastwood for home kits.

Tony Hallo has a write-up about his experiences in the Tech Tips section of HBOA Online: http://www.inwave.com/~bacchus/HBOA/.

Autopower sells SCCA/IMSA-approved roll bars and cages for H-bodies, bolt-in or weld-in. Their cages may or may not be NHRA-approved.

S&W Race Cars sells NHRA/IHRA/NMCA-approved bars and cages, weld-in. The 10-point cage is pre-bent but will need to be cut to fit.

Alston Race Cars (in IL) sells a 6-point cage, but only the main hoop is pre-bent. The installer must cut and bend the remaining pieces as needed. The 8-point cage might be pre-bent.

For Vega: Strong Arm brand part # 4717, about $40

For Monza: Monroe makes replacement struts, part # 901250. These are the same as used on the Chevette and Citation. Or, Strong Arm barand part # 4445, about $40.

One option is Jeg's front clip.
Kirk (kcdragmonza) writes:
"About two years ago I bought the full frame and 12 pt. cage from them. The clip must be used with the frame and rollcage because they are what hold the clip in the car. The two frame rails and rollcage tubes are all that hold the clip in place.

Because of the angle of the rails any swaybar used would have to have custom mounts welded to it. All other suspension pieces are used except for the Pinto [steering] rack which calls for the spindle holes to be drilled oversize to accept the tie rod end. Jegs recommends using "lightweight 4 cyl. springs" and the upper A-arms are switched from left to right."

One option is to get one for an '82-'92 Camaro and modify it to fit. It will require some basic cutting and welding.

First, remove the hinge pins; replace them and the brass bushings. If that's not good enough, the holes for the bushings are probably messed up--weld them up and re-drill new ones. Finally, loosen and adjust the door striker, then tighten it.

John B (vegadad) says:
"In my experience the answer is yes. The only problem you may experience is where the 71 - 73 front facia (upper Grill piece) mounts to the chassis at the bumper line. On the 71-73s there are two bolts per side that mount to an extended piece of sheetmetal at the battery level on either side. You may fabricate this extension by test fitting the front end and see what's required. Other than that you shouldn't have any problems.

Take a look at the donor car, or if you are installing fiberglass, the mounting holes will be identified by depressions in the new piece. I've seen at least two racecars that have had this done. Be patient and take your time."

Dan (vegon71) adds:
"What I did was drill out spot welds on radiator support panel on donor car which was a 71 hatch. It fit right up in my 74 wagon. I had to open up the radiator opening for more air intake."

Ken (mahoy78spyder) says:
"The four Monza Mirage panels were screwed or rivoted in at the bottom, and then attached at the top using a plactic V-channel strip. The strip itself was rivoted every 2-3 inches to the fender or quarter panel, and then the upper lip of the Mirage panel was tucked in neatly underneath that strip, thus hiding the rivots and providing a nice-looking, seamless line across the top of the panel. Unfortunately, the urethane panels were prone to warping, and the V-channels were prone to drying out and chipping or cracking and over the years they deteriorated badly. [...]

They are extremely hard to come by because no one wants to take the time to drill off each rivot carefully to save the strips. Most people just pull off the Mirage panels only and leave the strips for ruin. Unfortunately, your only option without those strips is to bond the top of your panel to your fender/quarter panel. Ironically enough, that is what Chevrolet did in one of their first attempts at a Mirage. Look closely at the Mirage in the hard-to-find 4-page Mirage flyer and tell me if you see any strips there."

John B (vegadad) writes:
"In order to make a Panel express from a station wagon you will need the following:

1. The panels--these panels are reinforced on the interior side to aid in holding them in place.
2. The interior Clamps--these attach to the reinforcing strip welded to the interior of the panel to hold the panels to the inside of the gasket, and
3. The gasket.

Tom (TheAstre) writes:
"To ease the effort of removing the windows, pull back the rubber from the inside, then spray in plenty of oil where the rubber contacts the body. The windows push out at the top front. I've worked them out that way by just pulling the rubber back on the inside, oiling good, and pounding the window out with my fist. It'll take some time, because they work their way out just a very little bit at a time. Don't pry at the window, it will crack into a million pieces."

John B (vegadad) adds:
"In addition to providing lubrication. There is a sealant on the outside of the gasket to keep water from getting into the interior. Some folks wrap twine around the interior side of the gasket, then firmly push the window out as you pull the gasket away from the body. Just the reverse of installing the window, if you've ever done that. Be careful as it's safety plate glass and if it goes it will shatter into beads. Take it easy and you should be able to save everything."

Then he adds:
"The rear Quarter windows are a snap to remove. I recommend starting on the interior at the lower rear point on the gasket where it comes to a point. Lift the seal with a wooden spatula, if you have one, or something flat & dull. Don't want to cut the gasket material. Work from the point in both directions, along the bottom and up the back part of the seal, a little at a time. The seal is glued on the exterior side with an RTV type material, (The same stuff your windshield is out in with.) Be gentle but persuasive and a little Stern (finesse) once the back of the window frame is loose the window and gasket will push right out. everything is apart you can remove the trim pieces."