Frame swap. Old style to newer GM

[Sal]

I have heard enough about the improved handling and ride performance that is realized on the Avanti equipped with GM's Monte Carlo frame that it has me considering the swap. I have already acquired an original frame to replace the one I have that has rotted through and has only the slightest hint of once having hog troughs. What modifications are necessary to a newer, (maybe 88?), Monte frame to make the changeover possible from a 72 to 88 or so. Are there mounting plates to be added, a good deal of welding etc? Has only undertaken this?

Thanks for the help.

Sal

[ernier]

Having both a 64 and 88 I don't believe that the 88 under normal driving conditions handles or rides any better than my 64. The 64 has a virtually new/rebuilt suspension, all pieces except front coils and the 88 is a low mileage car with new shocks and tires.

The 88 is more "jiggly" and doesn't feel as solid as the 64. It is quieter and has quicker steering but those two things aren't different enough to warrant a frame swap like you are considering. Besides, you would have to alter the nose and maybe the rear quarters to adapt the Monte frame. If you take the front bumper off an 88 you will see that the bottom of the fenders and lower valence have been removed to accomodate the frame extensions and bumper supports.

If you rebuild you 'new' Stude frame's suspension you will have a very comfortable, tight and nice handling Avanti. BTW, I noticed the biggest improvement after replacing the rear leaf springs. Second on the list was front A frame bushings upper and lower, with original type rubber.

Add to the above, new lower steering column bushing, tightening and properly shimming the body at the radiator support, sound deadening material under the carpet, headliner and dash. Sealing all openings to the passenger compartment both from the engine compartment and trunk area, new gas shocks and keeping the tires inflated at no more than 26 rear and 28 front all contribute to the comfortable 'ride'.

IMHO...

ErnieR

[Sal]

Having both a 64 and 88 I don't believe that the 88 under normal driving conditions handles or rides any better than my 64. The 64 has a virtually new/rebuilt suspension, all pieces except front coils and the 88 is a low mileage car with new shocks and tires.

The 88 is more "jiggly" and doesn't feel as solid as the 64. It is quieter and has quicker steering but those two things aren't different enough to warrant a frame swap like you are considering. Besides, you would have to alter the nose and maybe the rear quarters to adapt the Monte frame. If you take the front bumper off an 88 you will see that the bottom of the fenders and lower valence have been removed to accomodate the frame extensions and bumper supports.

If you rebuild you 'new' Stude frame's suspension you will have a very comfortable, tight and nice handling Avanti. BTW, I noticed the biggest improvement after replacing the rear leaf springs. Second on the list was front A frame bushings upper and lower, with original type rubber.

Add to the above, new lower steering column bushing, tightening and properly shimming the body at the radiator support, sound deadening material under the carpet, headliner and dash. Sealing all openings to the passenger compartment both from the engine compartment and trunk area, new gas shocks and keeping the tires inflated at no more than 26 rear and 28 front all contribute to the comfortable 'ride'.

IMHO...

ErnieR

[Mel]

As Ernier noted, changing the rear leaf springs made all the difference in my '66, also. (I also put on new front and rear shocks.) My springs were so sagged they were sagged slightly beyond level, not even slightly curved upward.

Eaton makes springs for all kinds of cars and makes them up after you order them; they have the plans and make them up new. I was hesitant to order NOS springs from a Stude parts dealer thinking they might have lost some of their 'springiness' if left sitting around for 35-40 years, probably not but I certainly don't know. Anyway, I called Eaton (313-963-6820 www.eatonsprings.com) and they had regular and heavy duty springs -- same price. $479.00 plus shipping which was cheaper then NOS. They had two prices listed, one of which, I believe, was for a garage to purchase and the other for you and me. I told the guy on the phone I was having some work done at a garage (which was true) and could have the garage purchase them for the cheaper price and sent to the garage or he could sell them to me for the cheaper price and send them to me. He didn't hesitate at all, sold them to me for the cheaper price and sent them straight to my doorstep. Perfect fit.

As I said earlier, regular and heavy duty were the same price. I think they just add another leaf but I'm not sure. I got heavy duty and they really raise the back end of the car up pretty high. I think, to do it again, I'd probably get regular duty as the heavy duty probably set it up higher than the stock 63-64 which, as we all know had more of a rake than the '65 and on models. I like the aggressive rake but it is a bit much.

Good luck.