I have read conflicting information on whether or not I need to change the frame motor mounts when replacing a 307 with a 396. some aftermarket sites list 1 mount for all V8's, others state 307/327/396 are the same and 350 is different, or 307/327 are the same and 350/396 are different.
When I replaced the 350 with the 454 in my '70 back in '93 sometime, I just took the mounts of the mouse and put them on the rat..... (before I knew there was a difference) Still there today....
thats great because I already blasted and powder coated the 307 frame mounts and they are already installed on the rolling chassis. I do have a new set of 307/327 motor mounts so I can just use those, right? Just double checking because the big block motor mounts look to be a bit beafier
Just off the cuff, I would summize the insulation is twice a thick on the rat mounts because of a heavier mass and viberation reduction.. Thus the lower frame mounts........
I used mine! Just my near extinct 2 pennies, though! Other may and will sure beg to differ if you are going for the originality look!
There correct in that if you use the 307 mounts you will need the 307 engine mount as well. There are two part numbers for frame mounts for 69 as the 307 frame mount is taller than the 350,396 mount. For the 350 and 396 they used the new at that time interlocking engine mount that was thicker and would require a shorter frame mount. But you should be ok as long as you use the 307 non interlocking style of engine mount.
