[cougar101]

i have a 68 cougar with a 351C, and im looking to beef it up. gonna put in new cam, intake, carb ext. some real highflow stuff. and headers.

now right now the car has an almost new duel 2 1/2 inch flow-master exhaust system and im wondering if it will be beneficial to upgrade to 3 inch or will that be overkill? just looking to get the best flow possible. thanks.

 

[1969XR7Vert]

2V head or 4V heads? Chances are that your current system will be just fine/work well. However, I do not want to get into a "duel" with you to prove who's right :buck: (that's a joke, son).

 

[Cougrrcj]

Factory 70-73 351C-4V duals were 2-1/2, whereas '69 351W-4V duals were 2-1/4. 351-2Vs (W or C) singles were 2. 302/289s were all 2" AFAIK...

With a 3" exhaust you will lose a bit of lower- to mid RPM torque.

 

[cougar101]

4V heads. weiland EX-elerator intake. holley 750 double pumper. headers.

i definitely appreciated the joke as well :

 

[351CJ HELLCAT]

Too big exhaust will hurt as the heads are so big they need the back pressure unlike smaller heads. Wanna beef it up get it dyno tuned and youll be happy with the results.

 

[cougar101]

perfect, thanks!

 

[68XR-7351C]

You have the right setup. Headers, 2 1/2" pipe and a good flowing muffler. That is just right for a 4V Cleveland.


Chris