Are the PRC 237 heads too much runner for a mostly street driven 402? With my short block its looking at around 11.5 CR with a Cometic .040 gasket. I'm still trying to decide on a cam.


**Mods, I meant to post this in the Internal GenIV section. Please feel free to move.

 

Personally, i'd do it! I want to do them on my TBSS on stock bottom end.

 

No problem. They will work fine just get a good tune. Getting the air fuel right through out the rpm range will take care of any lazy air that might crop up at lower revs.

 

It the low end that has me concerned. I have little doubt they should make good power on the top end.

I was planning on trying to reuse my old MTI STG 2 heads with 2.055 In 1.6 Ex, but they are 853 castings. They are up at TEA at the moment for some work, but I'm afraid I'm going to get to a point of diminishing returns pretty quickly with those heads.

I've only found a couple of posts in the dyno section, but the one with a posted graph looks pretty good, even down to 3K. It was still over 400 lbs tq at 3K which is more than my peak tq in my H/C setup. But my cam is really tame by today's standards (single pattern 222/566). Back in 01 not not many people were having success with the big sticks.

 

Not hardly...

 

With the cam you are running there isn't really a need to be worried about the low end of the power band. Cams like that make great low/midrange on stock displacement motors and with the added cubes, it should be a pretty sweet DD combination.

 

DRAT! The used set I was looking to buy was sold.

Word from just in from TEA is that my heads are going to need more work/money out into them that I really want to spend now just to upgrade heads later.

I really don't want to shell out the money for new AFR?TFS/PRCs at this point. I have been wanting to go rectangle port for this motor, but I don't not want to jump into a relatively new technologies right now just to see that I've put money were there are little gains. I did this with the LS1 heads back in 01. Now we know that the bigger 2.055/1.6 valve don't make anymore power than the stock valve seat heads in a 3.9" bore. But the prices of the rectangle port stuff sure is attractive. I was planning on having to get a new intake anyway.

 

Any particular reason you want to use the square port heads? Yes they make good power but they arent really doing anything that cathedral port heads are doing. Most people like them because they are budget friendly or they already have a ls3/7. Keep in mind you also have to get a new intake for the square port heads and your cam is probably not good for them. IMO just get a good set of cathedral port heads and make good power.

 

Looks like I'm iin luck. The other deal fell through and my offer was accepted.

You hit it on the head with the rectangle port. It was the cost as well as potential future growth that attracted me. I lost all interest in the car a few years back on started getting rid of my performance parts and sold my LS6 intake and had been running my old LS1 (mostly to meet local emissions testing as the car was never tuned and still threw EGR codes) so I'll need to get a new intake regardless on which direction I go. I recently scored a set of EV1 42lb injectors that I really did not want to have to change out or use adapters on. I also intend on going to a larger cam regardless if I went rectangle or stay cathedral. Just not quite sure yet as I was waiting on word on my old 853's.