I currently have an LO5 and I'm looking for suggestions for more tq between idle and 4500 rpms on a budget.

Should I stick with the TBI or is TPI worth the swap?

I've heard the swirl port heads are very good for low end tq, is this true?

I plan on doing some 1 5/8 headers and a single 3" exhaust.

A stroker kit is in the future, but will probably wait until next winter for that.

 

TPI is a torque monster ive seen dyno results of 305s that put out close to 400 foot pounds of torque. It also just so happens that it only performs well up to 4500 RPMs on a 350. So this would make a great street motor or choice for a low end torque emphisized build up but not the greatest for high end hp. Also without pretty decent mods it wont work to well later on with the 383. TBI isnt a bad set up per say but it was GM's economical way of produceing fuel injection. Im sure theres 100 threads on comparisons between the two so i wont waist your time with that but something to concider anyways. The exhaust you picked out sounds fine i havnt heard much on swirl port heads but im shure someone else will chime in on that.

 

I may be going a turbo route vs stroking. I need lots of low end but with a good flat tq curve to at least 3500 rpms.

 

Well how much torque are you looking for? I know its more of a feel kinda thing but are we talin like 300 350 400 as a ballpark? I think your on the right track to get high kansas flay torqu curve genrally speaking you need a tame big inch motor. How big depends on how much though.

 

This for a offroad 4x4/rock crawler by chance?

 

Yep K5, figured I'd get some good info here right at home. I hope I don't get in trouble. It is more or less a camaro engine. 4.88 gears and 35" tires.

I would like to make 400+ ft/lbs without stroking. 450 would be much better.

Needs to have good off idle power for towing and a healthy midrange for highway and muddin'. I tend to stay away from rocks.

 

Well if you didnt want to stroke a motor ide say your pretty much stuck with a 400 SBC a big block or a forced induction SBC. The thing i dont like about FI is the fact that your not running max boost in the lower RPMs where your really seem to be looking to have it lol. With a good sized turbo you can do well but its still not "perfect" belt driven FI set ups are even worse only producing max boost in the high RPMs. Now if your stuck with a SBC and you dont want to use a 400 then FIs your best bet but ide seriously concider a big block if you can.

 

If I go turbo, I plan on using a very small one, one that will spool quickly and get all 5 or 6 psi in by 2500 rpms would be nice.

I could do a turbo for the cost of a junkyard 454 I think.

The plan now is to get some shorty headers, ones that I can flip or reverse later for the turbo, do the rest of the exhaust, drop on the TPI, and change the cam. Then I'll see where I sit, if I really need more tq from idle to 2500 rpms, I may consider a big block.

But I'm thinking TPI, swirl port heads, the proper cam, and tall gearing will be all I need.