got a 89 305 tpi and wandering if an upgraded intake manifold would give me any performance benefits and if so how much am i looking at. what is a good manifold and whatis the easiest one to replace????

 

Change your runners before anything, SLP or Holley make good intake kits for our cars. I'm sure someone on here has other suggestions, do a search for threads on this topic, you'll learn alot...
Try Edelbrock they have a runner and manifold setup. If you do these mods you should upgrade to K&N air filters and exhaust, especially some headers, the stock manifolds are very restrictive. Exhaust mods will help take advantage of the intake mods......

 

what headers would you suggest are good plus are easiest to install

 

You'll need headers and y-pipe to your cat, Hedman, Edelbrock, hooker, they are all good, I have Hegman TTY coated, whatever you can afford...

 

I have K&N lifetime airfilters w/10K mi on them and an airfoil for a TPI throttle body if you need $25 for ea or $40 for all... PM me if interested. Problem w/TPI is the runners and intake do not breathe well, if you modify the intake to take advantage, you should upgrade the exhaust, if you can't afford it all, you can do it one piece at a time.

 

im already running k&n's but what exactly is the air foil and what will it do for me?

 

It smooths out airflow into the throttlebody, angled/Curved piece seperates the two barrels on the throttle body, Jegs sell 'em, Summit, etc. Cuts down the turbulence in the air coming in , allowing better flow.
The Holley piece is $60 @ Jegs part #510-120-140 for TPI and LT1. Aftermarket throttle bodies have it molded in the front, this piece bolts right in. The one I have is a Holley...

 

Any hp gains?

 

Minimal, advertised as 10-12, more like 2-3, however, smoother more tractable power throughout the entire rpm range, more consistency and efficient use of what you already have. Better mileage also... Works well w/ increased airflow of K&N filters....

 

what intake manifold should i look for. its tpi not carbureted does that matter which intake manifold can i replace with the stock one without doing any major work to make it fit?

 

Holley stealth ram is supposed to be good??