Hallo
Is it anyone who knows what pulley size to use for 6 psi on a stock LT1 ?

 

4" pulley for 6lb boost

 

are you sure? my 6psi kit (ordered for a head and cam engine) came with a 6,45 crank pulley and a 4.13 chargerpulley.
and that gave around 6 psi at 5800. so i assumed that 6 psi on a stock engine should be a 4.25 pulley or so.
Or is it for 6 psi on your 383 cc305 engine you use a 4 inch?

 

My old 4.5# stock set up came with a ~6.5 crank pulley (not the 7.65) and with a 4.5inch blower pulley. If I remember correctly the correct 6# blower pulley for a stock motor is 4.25in. I am running a P1SC too.

Thanks,
Claude

 

Thats make sens to me, a friend of mine ordered a 6 psi intercooled p1sc kit, but there was a missunderstanding and it was deliverd whith 7.65 and 4.25 (8psi) so instead of returning parts (from sweden) hes gona use my old 6,45 but i was not sure if its the 4.13 or 4.25 he should have.
thanks