just got a rough 76 l48 auto for 600 bucks, been sitting 15 years, frame is rusted out. so, got an 80 parts car with good frame. curious to know if theres anything to know before attempting the swap, and if the 80 rear bumper will fit my 76. any advice is appreciated. thanks, josh

 

I can tell you that I have an '80 rear bumper on my '74 so I think it will work on the '76.

 

I don't know the answer to your question, but here is a pic of my 80' frame. Maybe someone can post a pic of a 76' frame or know the answer.

 

The 80 frame will not swap under your 76 without more work than you want to do. The rear of the 78-82 frames account for the relocation of the fuel tank required by the big back window.

http://www.71corvette.com/frames.html

 

The biggest issue is the rear suspension. You have the steel crossmember vs 80's aluminum batwing. You can see the tabs for the batwing in the pic above.

Rob

 

since the 76 been sitting for 15 years (outdoors maybe?) and has a rusted out frame I think you have two parts cars.... part them both out and buy a better car

 

If you use the 1980 rear, it should be a pretty straight forward swap. If you want to use the 76 rear, your looking at a fair amount of work, to install the 76 rear.

All of the body mounts, are in the same location, on both frames. The front and rear frame ends, and front suspension, are all the same. You'd probably need to use the 76 shocks for the rear bumper, as the 80's are a different diameter, and the 80's are a bit shorter too. You'll also want to use all of the 76 bumper supports and brackets.

You'll need to use the 76 gas tank and gas tank support, since the 80 support is shaped different and mounted further forward, than the 76's support. The tank supports threaded mounting holes, in the frame, will need to be re-positioned, to use the 76 support.

The only other issue I can think of, would be the transmission crossmember. The 76 crossmember, has holes in it, that the exhaust system goes through. On 80's, the crossmember doesn't have the holes, but instead is just pinched down on the right hand side, so the pipe will go under the crossmember. If both cars are automatics, this won't be a big deal. Automatic cars use a bolt in crossmember, and you can swap the 80 crossmember, for the 76 piece.

If the 80 frame is for a manual, the crossmember will be welded in. In this case, it may be easier to use an 80 exhaust system, than to cut out and weld in, the 76 crossmember.

Now to the bigger issue. If the frame is so rusted out on the 76, have you checked out the rest of the car???

A car sitting outside long enough, that the frame needs to be replaced, likely has other rust problems. Have you checked the windshield frame, and a-pillars, for rust. The frames often leak around the stainless trim, causing the frames to rot out. When this occurs, it often causes rust issues in the cowl and door hinge area (the birdcage). The t-top bar is also known to rust out.

What kind of shape are the floors in? 76's have steel floors, and due to the t-tops and windshield leaking, they often have rusted floors. The rocker/sill area is also prone to rusting out.

If your 76 has additional rust issues, it probably isn't worth putting the time and money into. There are just too many reasonably priced good 76's out there, to make it worth while to end up upside down in a rust bucket.

 

thanks for the replies! i know i should start with a better vette project, and may just part them or sell them and get a better one. my 76 is pretty rusty, someones already replaced the floors more than 15 years ago, so even then it was a rusty car. not good.

 

Take a good look at the windsheild Frame, under dash and the inside of the Doors before deciding on what to do. Wile your at it look at the Body mounts and see if anything is left to bolt on the new frame. If any of these are in bad shape, you can figure the Bird cage isn't much better.