Headers.....holding motor back?

[SactoJim]

Got my motor out of my truck due to a couple bad cylinders (heavy leakdown numbers) and will take the opportunity to replace the flat tappet cam with a hydraulic roller (more aggressive). Without hard dyno numbers, I'm guessing the motor makes in the neighborhood of 500hp. Truck is only occasionally street driven and I have no plans of taking it to the track, so I want decent street manners with adequate vacuum for power brakes.

Specs....383, Weiand 142 blower, ELdy RPM heads, about 9:1 static comp,800 Eldy carb, all forged Eagle rotating assembly and SRP pistons.

current cam specs:

Isky flat tappet hyd,
Int. lift/dur 490/274
exh. lift/dur 510/284
Int. @ .050 - 226
exh. @ .050 - 236
112 deg lobe centers

Right now I'm running a set of Doug Thorley tri-y headers (5/8" primarys/2.5" collectors) that I've had for a long time, fit very well, good ground clearance, and have never given me a problem....nicely made header. My main question is if I'm giving up much hp with these and is it worth spending the money for some 3/4" primary headers or not?....and if so, the challenge is finding some that fit well and give me decent ground clearance. Current exhaust is 2.5" all the way back with an H pipe.

Also.....is it worth it to do some port work on the heads why I have it apart?

I should probably leave the whole thing alone because it ran very well, but it's just about impossible to not want some more out of it!!!

Any other advice for improvements is appreciated.

Sorry for the long read.....just trying to "paint a picture"!

Thanks....Jim