Re: How to tell the difference between a 352 and a 374

Posted by humanpotatohybrid On 2022/12/1 18:21:10

In 55 the 320 was used on the 5540 bodies (Deluxe and Super) and the 352 was on the Custom and Packards. In 56 it was 352 all Clipper + Exec, 374 all Packard.

Note that 55 and 56 engines, even 352, are not identical. 56 had higher compression ratios and there some other changes such as hardened clips for the valve springs that prolong life (IIRC).

55 C/R on all was 8.5 (claimed higher on Caribbean in ads, but service manual says they are all the same)
56 352's are 9.5
56 374's are 10.0

Also it wasn't uncommon for some 55's to end up with 56 352 engines in them over the years.

BTW what octane of gas do you use in it?