Which is more economical, best results, and most reliable?

 

PI heads hands down. You can get them used for as little as 200each i have seen them go on for sale sections of websites.

 

+1. The stock heads ported would probably flow about the same as PI's but after .500 the stockers would out flow the PI's. before i bought my ported heads, people wanted to charged me around 800-1500 just to port my heads, so i bought ported heads for 1300 and sold my PI heads for 200 to make up for some of the cost.

 

depends alot on the price and what you want the heads to-do, I've seen some pretty impressive #'s out of Steen Racing on ported non-Pi heads vs out of the box PI heads. now ported Pi vs ported non-Pi, thats another story and alot more $$ but they both can make HP.

 

What is it that you want to do? If you plan on adding a supercharger then the compression bump from the PI's isn't so great for that. I have seen ported NPI's from Renegade Racing that flow as well as St2 ported PI's but it is expensive...thats why i jumped on a deal for some used VTst2 heads instead of sending my NPI's out.
There is power to be had from both heads but a cheap set of stock PI's with the PI cams/intake will make a nice difference compared to the stock NPI setup.

 

I heard that after market cams wont fit on non pi heads. so if you plan on cam then pi should be the way to go.

 

Do you need a set of heads??? Stock, used PI ones, I mean?