Anyone using 1 3/4" longtube headers on there 351w for a 69-70 Mustang? I need to use 1 3/4" headers for a 393 in my 70 Mustang. I was curious what type of clearance problems I may expierence. I really don't want to remove the shock towers. Thanks.
Why do you feel you "need" bigger tubes? Going all out drag racing with it? or just for the occasional street driver? reason I ask, is I see all this crap about "bigger is better" for exhaust systems, but it's been my experience that smaller works just as well many times and unless you can run different components back to back, and down the track, you probably couldn't tell the difference in many cases. Take the Shelby type tri-y headers I have on my 331 stroker motor in my 89 Ranger, from all I've heard they're a huge bottleneck to performance to a motor like mine, yet I couldn't be happier with the results, this thing makes power from 1500 to 6500 ( maybe more, but I don't feel the need to stretch things)
I looked for 1-3/4 shorties as I felt they might be better for a 393 stroker but couldn't find anything. Since I went for torque over HP, probably the 1-5/8" are better for me anyway, but I could see where a 408 or 427 stroker would benefit. I think the 331-347 in most applications would be just fine with the smaller primaries.
I looked for 1-3/4 shorties as I felt they might be better for a 393 stroker but couldn't find anything. Since I went for torque over HP, probably the 1-5/8" are better for me anyway, but I could see where a 408 or 427 stroker would benefit. I think the 331-347 in most applications would be just fine with the smaller primaries.
I agree with you on the smaller primary for the smaller stroker or stock engine.
I bought from FPA a set of Step long tube (1 5/8 to 1 3/4) for my 418 stroker (427CID) and could not be happier. Got the best of both world HP and Trq. The main limitation that you will encounter is the size of the exhaust port and bolt pattern. If you have stock exhaust ports you will have to do the step header if you want the 1 3/4 because the bolt pattern will not fit.
Make sure that you chat with those guys about the HP/Trq you are planning on producing because, as you may already be aware, you need a little back pressure.
As a point of comparison, my engine dyno'd (carburated) @570HP with 530 ft.lbs ... still waiting to dyno efi'd.....
Call Stan @ Ford Powertrain 253-848-9503. Very friendly and knowledgeable guy.