Hi there, I bought my car last summer and it had the motor rebuilt (5.7L) in it at one point. It currently has an LT4 hotcam, 10:1, Trick Flow 23 degree heads, SLP 1 3/4 headers, 3" exhaust, 58mm TB, MSD ignition. It still has the stock TPI intake on it. The car runs fine and makes decent power, but I know the stock intake isn't helping. I picked up an edelbrock base intake manifold which i plan to install over the next couple of months. It isn't ported and I probably won't port it this year due to a lack of time. As of now, I still have the stock runners as well. I'm looking for a decent running car with good manners, and something that is going to work well out of the box. I know the current setup isn't matched well, and I'd like to at least correct that the best way I can. That said, how much would I be giving up if I used the stock runners with the edelbrock base, or went with a set of unported aftermarket ones? I've been waiting for a used set to pop up for sale but I haven't seen many listed. I want to keep the EGR so I do not want to go the stealth ram route.

 

You are probably costing yourself ~20hp with the factory runners (especially at the upper RPM range). The stock runners are extremely restrictive, keep in mind that GM originally designed the TPI for the 305, not the 350. I highly recommend upgrading to AS&M or Accel runners. I went with SLP runners and now wish I had more material to work with for porting...

Hope this helps.

 

have you ever run the car at the track? if so, what mph are you trapping?

if you want to get that intake ported i have a friend in leamington who is an excellent porter.

 

http://www.firstfuelinjection.com/products.htm

This, what im doing. ^^^^

 

I ran it back in the summer, it was my first time with it at the track. I don't have the time slips but i think the best was a 2.2 60ft, 13.7@103mph.