ok well i have an exhaust guy that says he can make me some custom runners. my question is....

would there cause any problem if i were to raise the whole plenum upwards to make the runenrs longer.

i do have a cowl hood so no problem with clearance.

 

Is there any paticular reason you would want to make the runners longer?

 

not sure maybe just for the hell of it.

increase airflow?
different?

i dont kow, just curious i guess.

 

Well, the tuned port long tube runners (stock) were designed to build buckets of torque down low in the RPM range. This is exactly why big cams dont work well on a LTR TPI. Most, if not all, aftermarket intake manifolds, are designed with a shorter runner, so you can spin the engine higher in the RPM range, and have more useable power in that range. Of course, you'll give up a little bit of your low end torque in the tradeoff. Also, hood clearance is also an issue. Even if you did raise the plenum up, it most likely will interfere with your hood, as the Holley StealthRam does on the f-bodys. The after market has alredy covered the bases with changes in runner length. You might want to check out the "Alt Intake Board", as there are single plane conversion intakes there, as well as the S/R, M/R, and HSR, manifolds. You might even see a mention of the First, and T-Ram as well.

 

thanx. also some more questions.

since im gonna be getting a 52mm throttle body, ported plenum, runners, and intake manifold would i have to get bigger injectors, FPR and stronger fuel pump?

 

Is this for the 305 becuase they really don't need THAT much air- especially for a low RPM engine (that's what it'll become with longer runners). Seems like you're taking it the opposite direction of every aftermarket company so I'll have to give this idea thumbs down.

 

I really recommend staying away from the throttle body. You really don't need it, and you won't see a difference. stocker flows 780 cfm, more than most modded 350's need. - as for the runners, longer would only kill more top-end, if anything, you would want shorter, but unless you move/remove the egr, you can't go shorter. stock 19 injectors and the stock fp will do just fine for WAY more hp than you're looking at. - get the afpr, port the plenum, port the base, and get some runners. Don't waste your money on the rest. - do you have FULL exhaust? as in headers, y-pipe, cat-back.

 

kool sounds good. yeah i got slp coated headers, no cat,3" all the way back to flowmaster (dont remember the series)