i bought a gen vi 454 over the weekend with the intentions of using a 4.25 crank in it for a stroker motor but i ran across a 4.5 forged crank that aparantly came from a mercruiser plant that closed down. i have read allot online about about the 4.5 crank and its one of those subjects that has allot of people saying it can and cannot be done. does anyone have experiance with the 4.5 in a 454?

I would not do it in a low deck block.

4.5 does well in a 10.2 block, you would have a bad rod angle and very short piston in a 9.8 standard block, just an opinion.

I read more and more people doing 4.375" in a standard deck 454/502 and not having any problems, but I have never read anyone saying it would be a good idea to use a 4.50" in a standard deck.