Big Block Swaps?

[39F]

If you have to buy a crank nowadays might as well go for the 4.25" crank. I have built several 4.25 stroke engines and they run well. My last one was a 565 that made 980 hp at 7200 rpm and 795 torque at 5300. It had no problem revving.

i got a good scat 4" crank but want more power I figure sell it and buy a 4.25 or 4.375 crank ,I got a nice std bore block

 

[bracketchev1221]

i got a good scat 4" crank but want more power I figure sell it and buy a 4.25 or 4.375 crank ,I got a nice std bore block

Stick to 4.25. 4.375 needs a lot of headflow to get the benefits.

 

[39F]

Stick to 4.25. 4.375 needs a lot of headflow to get the benefits.

320cc ports not big enough? I mean they are factory heads not the greatest flow but still fairly big, I will not port these heads being they are original LS6 heads matching pair too June of 72