Thread: 4.2 to r380

Originally Posted by 400HPONGAS

Bigjohn , when you say you have a stroker crank , is it the 3.030 stroke one ? fitting that will only take it out a 3.5 to 3.8 .So obviously you would be fitting the 3.9 Liners and pistons bringing the bore up from 3.5 to 3.7 then that will make it a 4.2 ? But if you had a crank with 3.330 stroke and just 3.5 bore then that would be 4.2 as well !
Allways wondered why you cant fit the 4.4 P76 3.5" stroke crank , given the right rod length and Piston CR Probably wont fit in the case.Still ,I fit a 3.875 crank where once 3,030 was on my holden V8's (308 to 400 CI), Lots of grinding and grouting !!Just dreamin !!

I actually measured and calculated the stroker crank in the 3.5 block and it came to 4150 or thereabouts. Can't remember the measured stroke.

The reason the 4.4 crank isn't used is about the main bearing journals being bigger, and it's not a very strong crank either.