No, doesn't matter. The only reason the intake would be different for a 351 would be that the heads would be a little further apart.

Ok got it that the blower intake will fit to either heads without issue.

Regarding our performance application, buying after market, should we?
- buy 302
- buy 351
- arbitrary

Why?

Also, the difference between the 289/302 intake and the 351W intake is that the 351 is wider due to the block being taller.

Performer RPM 302


Performer RPM 351

Buy good aftermarket heads in the 185-195cc range. The best flowing SBF heads are the GT40s that cam on the Cobra's like mine. I replaced mine with box stock AFR 165's and picked up 50hp.

Ok, got it. Out of curiosity, BRUTAL sugested 190-210 and you're suggesting 185-195. What's the theory and why did you guys select slightly different ranges of intake runners. Basically I'm targeting 195 since it's inside both your ranges.

Trans Axle and Tires
 

Ok we know our trans and it turns out the stock axle is 4.1. Assuming a 255/60x15 that gives us this, which is probably not enough top end. Maybe we need an even taller tire?

You should be able to spin that engine and make power to 6500 with the right heads. I would spin it up to 6000 before, but because of the heads, power would die off about 5500.

I think 210cc is too much for our little 306 with the rpm range we are in. If this was a 347 or if we were going to change the cam and spin this 306 to 8000 then I would agree that we should run 200-210 but not with the 306 and a max of 6500rpms.

This engine is equivalent to what I'm running in the Cobra with the exception of a root instead of a centrifugal. I'm running AFR 165 heads and a Crane 2040 and it pulls strong to 6000rpms. On a chassis dyno I put down 433rwhp with the supercharger belt slipping at 5300rpms. I would have put AFR 185 heads on originally but I still had the stock bottom end and the stock pistons won't clear the larger valves in them. I now have forged pistons that will clear the larger valves so an upgrade is in order one day.

Head bolts are different. 7/16s on the SBC and 1/2 inch on 351w. BUT, if I remember correctly, there are SPECIAL head bolts for that. Anyone??


"BTW, what about intake and carb, those seem important too. :nuts:"
I though we were going blower?

The reason I picked 190 to 210 is the difference between manufactures flow rates. Some 210cc flow about what a AFR 190cc does in the mid lifts. AFR around 190cc would be about perfect. But, you said cost was a factor.


Everyone has different ideas on what to use. Lets figure our cost factor and THEN we can pick our intake runner based on manufacture flow rates.:drink:

Another thing to keep in mind is: An NA motor drags the air/fuel into the cylinder- a forced induction pushes the air/fuel in. Port velocity in small NA engines is VERY important. BUT, Forced Induction is pushed thru port and port size (to a limit) can be bigger than on a NA motor.