Big block hardware differences

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02-24-2019 | 09:34 AM

sandslot

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From: Waterford, Michigan

Big block hardware differences

Is there a simple list of differences between a 1987 mark 454 in a 1996 Gen VI 454? The later is fuel injected, but valve covers? Exhaust manifolds? I thought about comping the part numbers!
Thank you!

02-24-2019 | 10:01 AM

f_inscreenname

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From: Pasadena, MD

Exhaust is all the same. Valve covers also. They are supposed to be a direct replacement for the earlier years. Not saying the internals are not different. There is a few changes inside.

02-24-2019 | 12:36 PM

Camalot

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The main difference between the mark 4 and Gen 6 is the cam shaft and crank alone with the oil pan and chain covers, I use a forged mark 4 crank in my Gen 6 with a simple two piece seal conversion. You can't use a Gen 6 crank in a two piece rear seal block (mark 4). You can use a Gen 6 cam in a mark 4 just need the cam retainer plate which is a much better set up IMO. Gen 6 can use all the early heads with no problem just the Gen 5 which you can't!!