I just tried to install a set of Edelbrock IAS shocks on my '66. The fronts were fine but the backs seemed about 3" too short? I got them from Summit, part# EDL-34016. I double checked the part number and they are supposed to be the correct ones. Anyone else had this issue with the Edelbrock IAS shocks?

I'm doing a body off resto and had the same problem with the shocks I bought when attempting to install them, in my case QA-1 Adjustable's.

I used Bilstein's up front and, like you, they went in with no problem.

The rear springs will compress quite a bit with the body back on, so I decided to leave them off for now.

Pretty sure GM used the same shocks for quite a number of years on almost all of the cars.

On my 66 SS, the rear shocks were way too short (2-3 inches) with the body off and barely fit fully extended with the body shell on the frame. Over time as I added the interior, glass, bumpers, etc., the rear springs compressed enough that by the time I was able to drive on the road, the rear shocks never have hammered against the fully extended stop. I had new coil springs all around and I am pretty sure the springs have compressed (settled) some with the full weight of the car on them.

With only the body shell on the frame, my rear shocks were fully extended and pressed against their fully extended stop. Now, with the car 99% assembled and all the heavy parts bolted on, I cannot pull up on the rear bumper to make the rear shocks hit the fully extended stop.

Sorry for the long winded answer, but I think that without the full weight of the car on the springs and the springs broken in, the rear shocks will be too short when first installed.

Thanks to all for the encouraging replies. Nothing has been going right lately with my car. Every day it is some little BS issue that drives me nuts! At least the body is back on the car and assembly is in progress...finally.