When you say siamesed runners do you mean the whole runner is siamesed or just the ends like SLP runners. How would you even siamese runners there are all curvy and crap you could never get a dremel in there to get it all out. Just wonderin cause im going to need serios air-flow for my 400small block. I'm already pricin out how much the plenum will cost to get completely ported along with a edelbrock base manifold ported.

 

Well, being that stock runners separate from each other, you'll have an incredibly tough time siameseing the whole thing. If you want to port your TPI, I suggest you read the tech article here on siameseing the runners and intake. Madmax figured it out and put up some number results for it (and they were very good from what I remember. The thread must be somwhere, just search for it. Even though they talk about siamsesing SLP runners you can still siamese just the intake for good results. You can also siamese the runner to plenum ports for a kind of increased plenum area. There are a ton of places to port stock TPI for power gains. And if your running a modded 400 you'll need quite a bit more of breathing than the stock TPI has to offer.

 

Well unfortunetly i really can't afford to buy a Super/Miniram as they are nearlly $2K in Canada and that's an overly exorborent price for anyone to pay for a manifold. I was thinking that maybe id get a edelbrock base and some SLP runner and have those port matched a siamessed Cause they have higher flow rates then the stocker crap that is on the car as of right now. This car will mainly for street use anyways. Im more corcerned about torque. Which the TPI gives plenty of. The ported and siamessed intake would surely give me enough breathing room for this and be a happy medium between a minram and stock TPI. This motor will never see RPMs over 6000. Not with a automatic tranny anyways. My mods are those that basically stregthen the motor so i don't have worry about it so much.

 

It would probably be a good idea to never take the stock bottom end past 6 grand or even keep it there for long. If your keeping the car on the street then I suggest you do keep the Tpi and port it the way Madmax did. Look for other site for porting the TB and plenum too. They're just as important as the rest of the intake. If you want a miniram look at some of John Millican's LT1 intake conversion work. The poor man's miniram.