I've decided that non-variable boost just isn't for me on the street. I'm going to make some passes when the track opens and see how it does. I guesstimate its making about 700-725hp. It would be fantastic to hit 9's....

After I make my reasonably best passes, I'm taking the supercharger off and swapping the th350 for a t-56. Auto is boring on the road. A detroit locker is also replacing the spool.

Since my motor is all forged its a shame not to make some power or rpms to make use of it! I am running 200cc heads that flow about 260 @.600 I believe. I also have a Professional products Hurricane intake that supposedly makes better power than a victor jr.

My xr288hr stops making power around 6000 rpms with my 383 and this motor should have no issues spinning to 7500. I'd like to get my peak hp up close to 7000 rpm while keeping some street manners with a manual trans and 4.11 gears. The shop that put together my shortblock estimated the motor at 470hp based on experience with these heads and cam. If I could get that to that magic 500 number, I would be ecstatic.

I'm thinking a bump up in compression from 9:1, mild head porting, gasket matching, and a higher revving cam should get me there. Would I need a solid roller if I want to spin to 7000? Would the increase in power from a cam change be worth the money?

 

I agree that you are going to need more compression, even if you keep the same cam. That cam right now would really prefer more like 10:1 to be well matched in a N/A pump gas application. I forsee a change of pistons in your future.

Spinning big RPMs with a roller is a lot easier to do with a solid than a hydraulic. The boards are litttered with posts about power dropping off over 6000-6200 with what seem like pretty mild hydraulic roller setups. The ramp rates on modern roller cams are pretty astounding and it takes some serious springs to keep them under control- springs that end up being too much for the guts of a hydraulic lifter.

One other alternative you might consider to a solid roller (which will be an expensive change-over) is going the "less is more" direction. I'm talking about getting weight out of the valvetrain. Weight is the enemy at high RPMs in a valvetrain. Modern high tech beehive springs and their itsy-bitsy retainers can drop a ton of weight out of a valvetrain and require less spring pressure, keeping you from stepping over the line with hydraulic lifters.

I forget if it was Car Craft or Chevy High Performance did a hydraulic roller buildup similar to what you're planning and they had trouble stretching the RPMs up where they wanted them for peak power. Changing only to a properly chosen set of beehives and matching retainers stretched their usable RPM range by nearly 500 RPMs (up to about 7000 max).

Just something different to consider.

 

Wow. I'm running 977 valvesprings. 441 lbs/in spring rate. The ones comp recommended for the cam were 322, but I'm also running 1.6 rockers. I've had the motor to 7000 rpms once for fun even though I think it was done pulling by 6500 or so with the blower. Motor didn't miss a beat.

I'm worried that the cam is going to run out of air way before floating is a problem. 288/294 236/242 .555/576 (1.6). Having the power drop off around 6000 sucks.

So I don't know what I could gain from beehives.