what atvantages are there in a aftermaket intake manifold, and what are some good ones, i have a 302 (69)

 

Advantages: Better airflow (more power) and less weight.

Which one is best depends on your engine. For stock engines, stick with something like the Edelbrock Performer. The Performer Air Gap, RPM, Weiand Stealth, et al will give a bit more oomph in the mid-RPM range.

 

Caveat: Don't expect massive changes in performance simply by changing the intake. Do this swap only will leave you disappointed. It needs to be done in concert with a bigger plan of performance changes to your motor which would include intake, carb, spark, exhaust, heads, and cam.

 

The performer vs. stock 2v intake will net about 20hp, which is more that noticable. With a cam, however, that number can be much larger when comparing an aftermarket intake to the stocker.

 

agree... when upgrading from a 2 to a 4 bbl carb

 

ok so how much power would this gain, i put in a better cam, headers, new 4 brrl carb 750cfm , my heads have been ported and polished, and i get a aftermarket intake manifold

 

well i'll be the first to chime in here, and im sure everyone will agree...... your 750 is WAY too big. you need to be looking in the 570-650 range, and with your mods i would say closer to the 570-600 range.

 

Agreed, unless you have a full race 302, there's no need to go over 600-650cfm. As far as performance gains, that'll depend on how well the heads were done and to what extent, what cam, what intake and about 2358940563758902346949053 other things to factor in. Good heads with the right cam/intake can make a big difference though.

For example(and those wondering) I finally got to run my 67 this last friday at the strip, and with my street 302(570cfm carb, heads/intake/cam/exhaust/ignition/pullies and 3.00 diff. gear) on street tires it ran a best of 13.44 at 105mph with a crappy 60' time(2.159) because of traction issues(I made some adjustments to my traction bars that'll hopefully clean that up some). That was with medicore traction(best run)and no type of cold air intake on a daily driver sub 6k rpm pump gas car with highway gears. With a good launch of a hood scop it could prolly run high 12's on street tires, and it's not anything wild. So if your heads were done well and you pick the right cam/intake/exhaust, there's no reason why the engine can't put out 300-350hp easily. But again, it's gonna depend a lot on the heads.

Also make sure you have good suspension/traction devices and brakes. There's no sense in having a bunch of power that you can't control or stop. That's just plain dangerous and stupid