bigblock conversion

Asked by Apr 17, 2010 at 03:05 PM about the 1966 Chevrolet Impala

Question type: Car Customization

I have a 66' Impala SS 327ci auto car. I want to install a 396ci and a 4sp in the car. the car has smallblock frame mounts in it now. bigblock frame mounts are not reproduced.. The smallblock frame mounts measure 2-1/2 inches wide. bigblock engine mounts that I"ve seen measure either 2-3/8 inch wide or 2-3/4 inch wide too tight or too loose! what do I do now?? I was told to buy a bigblock "donor" car. (good luck) I was Also toldI could use the smallblock engine mounts, they will bolt up to the 396 and the smallblock frame mounts but how could that work??? the 396 is so much bigger!! If it did bolt right up , would the engine be sitting in the right spot for everything else to work properly??  Any expert advice would be helpful    Thanks Chris.................

8 Answers

66bigblock396, I'm doing the same conversion on the same car. Let me know what you find out onthe mounts..tks.

you have to change the mounts on the chasis, not just the engine.

1 of 1 people found this helpful.

TRIP65 is right. You can pick up big block "towers" on ebay or possibly a local junk yard. You might have to move the taller(big block) towers forward one set of bolt holes if you have two sets(the '64 C10's do), as you need to get clearance from the firewall. The taller towers will raise the engine up & forward to give you clearance on the cross member also. You would be surprised though that there isn't as much difference in the block dimensions as one would think. Anyway, I'm going through the same scenario with my '64 C10 as I pulled my 283 out & am dropping in a 409! I do see the big block mounts on Ebay often for your car & situation.

I'll sell ya the pair I have for $100.00 original GM not reproductions

3 of 3 people found this helpful.

who told you these mounts aren't reproduced? they sell hundreds of aftermarket frame mounts ,check ecklers chevy parts.

2 of 2 people found this helpful.

i cant really see that being a part that is not reproduced, big block swaps are pretty common in any 60s american car...

1 of 1 people found this helpful.

I don't know about the car towers being reproduced, but I know the truck towers are not reproduced, and there are a few original NOS GM's floating around, but it's easy to find used originals.

i can give you plenty of places that sell reproductions , & just to name a few. there everywhere. just about every classic chevy parts dealer has them .

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