701 Swap Question

[SkankyTheClown]

Hi guys, just picked up a SN SJ that I’m going to drop a 62T 701 into. The 650 in the ski has a Coffman pipe on it that I intend to use.

Am I good to run it if I do a little DIY porting on the aftermarket Coffman exhaust manifold and use a 62T manifold gasket? Also, does anyone know what the thread pattern is for the timeserts I need for the manifold? Thanks!

 

[mikidymac]

That 650 pipe might cause issues on a 62T if the headpipe/manifold diameter is too small.

 

[SkankyTheClown]

That 650 pipe might cause issues on a 62T if the headpipe/manifold diameter is too small.

Even more resrtrictive than the stock 701 exhaust?

 

[mikidymac]

Not so much as restrictive but if that manifold to headpipe hole is too small it will fry a piston. Factory pipe started making it bigger because of this. I don’t remember the size you want but some of the pros should chime in.