TheGageinator

Update . The head shop just called and said that the valves aren't seating properly in either head. $80 a piece to rebuild.

BabyGT

That's not bad. A 4.2 stroker will get you faster than a 3.8 but there's a reason there is a v8 in the GT.

LilRoush

I'm always a big fan of the using the 4.2L crank as the building block of a V6 build.
4.2L with a mild cam, good heads/intake and blower go a long way.

If you are going this far, a 4.2L bottom end with the SuperCoupe M90 top end makes a killer combo.

TheGageinator

What about the 4.2 heads and crank? Or one or the other with my 3.8 block. I'm going to re use my 3.8 block for sure

TheGageinator

im going to get my 3.8 heads ported while they are at the machine shop i think. trying to find a 4,2 crank right now

LilRoush

3.8L split port heads are the same as the 4.2L heads. The only real change you can make use of is the 4.2L crank. The other difference is the upper intake, but it's huge and won't flow as well as the stock/ported 3.8L.