can i use a flat tappet hyd cam from a gen 5 in a gen 6 roller block? If so,which timing chain and cover?

Why would you want to do that?

its a 525 sc engine with a bad block.Im having trouble finding a gen 5,but i found a gen 6.

100% agree... Eddie swapped my tappet cam out instantly...not enough zinc in the oils anymore. Go to hydro roller.... More power as well...

Not sure on the actual answer to your question, but I would def even use a stock or close to stock roller vs whatever I had in a flat tappet. If at all possible use a roller with even the factory lifter setup.

i agree that the roller setup is better,just trying to do the block swap.

Checkeredpast is doing a build for a guy who is retired and on a limited budget. We will all agree that a hydraulic roller would be better, but was just wondering if that is one way we could save some money for the guy being that we are having trouble coming across a Gen V block.

well yes you can, but would not...merc did it on the gen VI 525sc's, just rebuilt 2 early this year, but switched to new rollers from marine kinetics...Bob did a great job making them close to stock...

the cost to go backward would make adding a stock roller cheaper

Im having trouble finding a gen 5,but i found a gen 6.