I disagree with FastRunner on the lower. The AFR 165 is a small port head, and porting the lower would only decrease the velocity going into the head.
You disagree with Ed Curtis, too. He ported my lower Cobra. No before/after comparison dynos, though. The Cobra/GT40/explorer is a restriction on heads that flow that well. It's not about intake velocity. It's about port velocity, which happens in the head. The intake's long runners provide the wave resonance benefit, not the runner cross sectional area.
I love longtubes, and I always recommend them. However, with a small port head it really isn't cost effective to go with a high rpm longtube header.
Here again you are in disagreement with Ed Curtis who had me replace mac shorties with long-tubes. A great many comparisons also show long-runners pick up power in the low-mid range in comparison to shorties.
I think the JBAs will be fine. If money were not a consideration, I would go with the longtubes, but with that combo I don't think it will make that big of a difference.
I mentioned too that I'd drive it as is.
I also don't agree on the Lightning MAF. They are a little slow to respond, and you are better off with an aftermarket unit. The Pro-M you picked out is a much better unit. It responds faster and doesn't peak out like a Lightning MAF. 75mm will flow way more than that engine is going to suck in anyway. No need to go bigger.
Cool. I had a 75mm bullet on mine. I think this is a fine MAF, too. Can you tell me how a lightning responds slowly? Can you tell me how much air flow it takes to peak a lightning MAF? How bout a 75mm MAF? I don't know the numbers, but I'm curious.
Anyway, the point of my recommendation was in reference to swapping to a higher flowing intake with a much larger inlet. Cobra/GT40 intakes have 68mm inlets if memory serves. A 70mm TB with an inlet port is optimal, but a 65mm is right for stock. A 75mm TB on the other intakes listed is right, but I believe in having a larger MAF than TB. A 75mm TB is fine for a 331 or a 347, but I can still show documention that a 90mm works better. Worth the difference in price? Not to me, but only the user can decide.
Don't get bent around the axle chasing a peak power number. I think that combo is going to have a nice even power curve, lots of low end torque, and you are really going to enjoy driving it. I'd take a car with 250rwhp that jumps out of the hole and lays down a nice 12 second quarter mile than a car with 300rwhp that has to rev into the red to get moving and can't get a low 13 any day of weak.
i.e. you'll take a care that has addressed traction, gearing, and weight over the car that was only focused on engine mods. Chances are a 300rwhp 302 is going to make considerably more mid-range torque than a 250rwhp 302. Remember, stock block 302s are RPM limited. No matter what you do, main caps are going to start walking around over about 7k RPM. Usually, you're much better off just keeping it to 6500 RPM and lower. If you can find a strong 250 rwhp, I'll try to dig up my old AFR 165 combo for comparison.
In any case, the point is moot. The long runner intake small headed combo is not suited to high revving, and should be cammed appropriately.
