jp928
Well-Known Member
Getting ducks in a row before I start on my 3.9 rebuild, have some cam questions.
I have heard that a 3.9 cam was a good upgrade for a 3.5, having some timing advance, but have not found any information to back that up. The original cams until at least the SD1 had timings of inlet 30BTDC-75ABDC, exhaust 68BBDC-37ATDC. One cam listed for a 3.9, ERR5924 is listed as 30-75, 67-37 - almost identical (typo?). Another is ETC8686, listed as 32-73, 70-35, ie 2deg advanced. These 2 cams are listed together , as though interchangeable...?
I am not after a hotter cam than std, more interested in good bottom end torque and power, so - my question is - If I can only get an old std 30-75, 68-37 cam with a long nose, would there be a problem using a timing set that allowed me to advance the timing 2 degrees? I think Cloyes offer such a capability for taking chain stretch out after many miles.
Comments appreciated.
I have heard that a 3.9 cam was a good upgrade for a 3.5, having some timing advance, but have not found any information to back that up. The original cams until at least the SD1 had timings of inlet 30BTDC-75ABDC, exhaust 68BBDC-37ATDC. One cam listed for a 3.9, ERR5924 is listed as 30-75, 67-37 - almost identical (typo?). Another is ETC8686, listed as 32-73, 70-35, ie 2deg advanced. These 2 cams are listed together , as though interchangeable...?
I am not after a hotter cam than std, more interested in good bottom end torque and power, so - my question is - If I can only get an old std 30-75, 68-37 cam with a long nose, would there be a problem using a timing set that allowed me to advance the timing 2 degrees? I think Cloyes offer such a capability for taking chain stretch out after many miles.
Comments appreciated.
