What's the differece between large tube runners, and siamesed runners from Thunder Racing? I would like to put TPI on a mild 383, and am looking into how well TPI would work for it. Also, if I got those runners, would a stock TPI manifold work, if it was ported out to match the Thunder Racing ones? Thanks,

 

Siameses runners are joined. Large tube runners are still individual runners (like stock) but are larger to allow more airflow. A stock manifold will work but it will limit the potential of the runners. The stock manifold itself is restrictive too.

 

So would porting the manifold make it 'less restrictive' enough for a 383? Or would a newer aftermarket TPI manifold be better? Or a completely other combo? Basically I'm just researching a setup for a 383. Any suggestions? I know you are probably tired of these questions, but I really appreciate the input people. Thanks,

 

You'd be better off getting another manifold, the stock one just won't cut it, ported or not

 

I don't think it'll be to restrictive if it's only a mild 383.

The two real bottlenecks are the runners and the base, not the upper plenum.

TPIS makes the big mouth base manifold and they also make large tubes.

Edelbrock has a similar setup w/ a better base and runners.

You can grab a superram base and match it up with SLP runners or Large tubes as well.

All of these are approx. same price in the end, and I unfortunately do not know which base is the best, tho I would imagine Superrams. Whochever you decide, don;t decide to port the stock parts - I don't think ported stock TPI stuff will flow enough for a 383 mild or not.

If emissions isn't a concern, definitely consider an LT1 type intake or the Stealthram, can't beat those prices with a stick! not to mention that they outperform aftermarket TPI style stuff.

 

Hey thanks, I'm putting this in my daily driver, so emisions would be a factor. Currently, they don't have the sniffer test in my town, but I think they're about to get some in Austin, so it'll probably be a matter of time. But, the main thing, is power, with fuel economy. And the reason why I'm leaning towards TPI, is fuel injection would have better fuel economy while providing more power right?
I want to use the engine from the Monte mostly because it's free. Could I get aftermarket heads that fit that early engine? If so, would this be a good setup:
-->High-Flow TPI Baseplate from Edelbrock
-->SLP Intake Runners, 1985-88 Camaro/Firebird/Corvette SBC
I don't know which heads yet. Anyone, I greatly appreciate suggestions. Thanks a lot.

 

That base with those runners will perform substantially better than stock with an increase in powerband as well - this is well known around here. I think if you do this to your TPI upper plenum - go look at the work he did in the addy below - it should flow significantly better. However, it won't use the FULL potential of the base/runners but I think it would turn out to be a well breathing setup. Oh yes there is also some porting you can do that is right in the beginning of the plenum, the mouth goes without saying as well.

https://www.thirdgen.org/techbb2/sho...hreadid=147622