ORIGINAL: Eagle2000GT

I don't think 4v are worthless. There isn't any doubt that 4v heads flow better than 2v and that they do respond a little better to boost. I'm just not sure its worth the cost to convert a 2v to a 4v when its really easy for a 2v to make 420 rwhp. I can get there with just a pulley change or headers. But, I have chosen to stay at 385 because my car is a daily driver.

I don't have unlimited budget but when its time to rebuild my little 2v motor, I been thinking about puttingin forged rods and pistons (the stock crank is good to 650 rwhp), headers and a mid-pipe, a THR intake, S/C cams and increasing the boost to 14#. I do not intend to change the heads because stock 2v heads are good to around 600 rwhp. I've floated this idea with a couple of engine builders. They thought I would also need a 8-rib belt and dual fuel pumps but getting to 535 rwhp is possible with just those changes (600 hp at the crank).

For the cost of changing a 2v to a 4v you can install a supercharger. S/C 2v > 4v. After that horsepower is limited to the rods and pistons. S/C 2v = S/C 4v. Until the bottom is forged, then you can definitely get more from a 4v. But that is above 600 hp. Forged S/C 2v < Forged S/C 4v.