I think a set of Sport Tubes (or sweeper style headers) would net both hp and torque gains, but the Etops are a little small. Although the Etops will work just fine on your engine, I don't think you will see much gains from them over the manifolds.
Eddie

I have a set of cmi sport tube headers. Its sounds like I should pair them up with the motor, however I am getting mixed reactions. I will have t e-mail Dustin and see what he suggests. Thanks everyone.:boat:

Looking at the Imco site, it seems the Powerflow was designed for stock replacement. If this is the case headers would certainly make more power accross the board. I would think in your application 2 -2.125 primaries would work best and leave a little room for improvement. I run the 2.375 on my 598.

thanks gpm, I will have to measure the primarys when I pull the exhaust off my other engine. I am steering towards keeping the CMI's sport tubes on the 598. How much more pomies to you think? 20hp or more............:D

thanks for the great head work on my small blocks .( It was ten years by now)

It's to hard to guess HP, if you do run the headers make sure it doesn't go lean and melt down. If you have to add fuel you're making more HP.

for sure we will have to put the air fuel ratio monitor on the engine to make sure, I certiianly woudn't want a melt down. Better to be alittle on the rich side.

A little more boost, a little more fuel, get that thing up around 1200hp,

GPM I like your train of thought. For now I will stick to the upper 900's until I put a new drive on it. I would love to put a Arneson but very hard to find used. Mabe IMCO Xtreme. As you said I am sure there is alot more hp to be found.:eek:

How do you like your 598. Is is whippled and how much boost hp are you running if you don't mind me asking.