New block vs Old
Pro
Joined: Mar 2000
Posts: 669
Likes: 80
From: NE USA
One piece rear main seal, different crank, different flange = different flywheel bolt pattern = different flywheel.
Best thing is, there are some threaded bosses in the lifter valley that hold down a sheet metal "spider" that holds factory roller lifter retainers. Basically roller cam ready!
At some piont (early to mid 90's) there is no hole drilled for the fuel pump push rod if you want to run mechanical fuel pump.
I used a salvaged block, it had the tins with it so I'm not sure about the timing cover.
Best thing is, there are some threaded bosses in the lifter valley that hold down a sheet metal "spider" that holds factory roller lifter retainers. Basically roller cam ready!
At some piont (early to mid 90's) there is no hole drilled for the fuel pump push rod if you want to run mechanical fuel pump.
I used a salvaged block, it had the tins with it so I'm not sure about the timing cover.
Senior Member since 1492
Joined: Aug 2000
Posts: 87,915
Likes: 156
From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
'65-90 (maybe 91 not sure) are Mark IV blocks. I have an '87 454 and used 65-90 parts.
90/91 started the next generation.
90/91 started the next generation.
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Depends if you are talking BB or SB.
On the SB, flywheels are different due to the 1-pc seal, oil pans are different. Other than that most everythng else interchanges. Motor mounts are same, all holes in same basic place. Balancers interchange, as do starters, pistons, and rods. Not sure about the timing cover, it may be the same as late-70s up. Basically it is a bolt in swap if you have at least a short-block plus flywheel or flexplate.
On the SB, flywheels are different due to the 1-pc seal, oil pans are different. Other than that most everythng else interchanges. Motor mounts are same, all holes in same basic place. Balancers interchange, as do starters, pistons, and rods. Not sure about the timing cover, it may be the same as late-70s up. Basically it is a bolt in swap if you have at least a short-block plus flywheel or flexplate.
