454 block + 427 crank - having a tough time with numbers

[Gary K.]

Thanks up front for all the help I'm getting. My '73 CE block 3999289 is shown as 454ci. Crank 6223 (cross drilled) is for 396-427. TRW Pistons #3888304. GM Connecting rods are 6" center to center. Cam part#3863144. I'm having a hard time figuring out what I got here - did GM use the CE 454 blocks for build-up of 427's in early 70's? Block has PASS, Hi-PERF, 4-bolt mains, a hi=perf oil pump assbly, etc etc.

The car has been in family since 1969, engine swap was in 1974 I know who did it, got the receipts, my Dad says it was a straight crate to car swap out and no rebuild has been done until now. Unless the '74 mechanic secretly built a frankenstein motor (albeit a nice one) I'm stumped. Any help much appreciated...

[Michael H.]

Re: 454 block + 427 crank - having a tough time with numbers

Thanks up front for all the help I'm getting. My '73 CE block 3999289 is shown as 454ci. Crank 6223 (cross drilled) is for 396-427. TRW Pistons #3888304. GM Connecting rods are 6" center to center. Cam part#3863144. I'm having a hard time figuring out what I got here - did GM use the CE 454 blocks for build-up of 427's in early 70's? Block has PASS, Hi-PERF, 4-bolt mains, a hi=perf oil pump assbly, etc etc.

The car has been in family since 1969, engine swap was in 1974 I know who did it, got the receipts, my Dad says it was a straight crate to car swap out and no rebuild has been done until now. Unless the '74 mechanic secretly built a frankenstein motor (albeit a nice one) I'm stumped. Any help much appreciated...

Gary

If someone ordered a 427 partial engine from Chevrolet in the early 70's, it would have been assembled with a block that was also used to build 454's. I had one.

[Joe L.]

Re: 454 block + 427 crank - having a tough time with numbers

Thanks up front for all the help I'm getting. My '73 CE block 3999289 is shown as 454ci. Crank 6223 (cross drilled) is for 396-427. TRW Pistons #3888304. GM Connecting rods are 6" center to center. Cam part#3863144. I'm having a hard time figuring out what I got here - did GM use the CE 454 blocks for build-up of 427's in early 70's? Block has PASS, Hi-PERF, 4-bolt mains, a hi=perf oil pump assbly, etc etc.

The car has been in family since 1969, engine swap was in 1974 I know who did it, got the receipts, my Dad says it was a straight crate to car swap out and no rebuild has been done until now. Unless the '74 mechanic secretly built a frankenstein motor (albeit a nice one) I'm stumped. Any help much appreciated...

Gary------


GM DEFINITELY used blocks designed for 454 applications to build up 427 engines. In fact, the GM #3963512 block used in PRODUCTION for late 1969 Corvette big blocks was, basically, a 454 block. This and other 454 blocks were also used for 427 SERVICE engines after 1969. Basically, the only difference between 427 and 454 blocks is the extra clearance for crankshaft rod pin clearance. So, there's absolutely no reason a 427 could not be built using a 454 block. If a 454 is built from a 427 block, though, extra grinding for clearance may be necessary.

The 3888304 pistons are 427 pistons. The "6223" crank is a 3.76" stroke 427 forged crankshaft. So, your engine is a 427. Period. The 3863143 (cast GM #3863144) camshaft is a camshaft originally used for both 396 and 427 (L-78, L-72, L-71) and 454 (LS-6) engines.

Assuming your rods are stock GM, they cannot be 6.0" center-to-center. All 1965-74 Corvette big blocks used rods of 6.135" center-to-center dimension.

[Gary K.]

Re: 454 block + 427 crank - having a tough time with numbers

Thank you ten times over!!! I was going nuts trying to piece together what may have happened in a garage in Hyannis MA 40 years ago.