Hey guys, I was thinking about getting a new set of heads for my second 91 GTA. I was just going to do a simple cam and head swap. I can get a good price on a set of Dart Pro 1 aluminum 200cc heads with 58cc combustion chambers and 2.02 intake and 1.60 exhaust valves. Are these heads too big for a basically stock 350 with an SLP 510006 cam? Thanks in advance for any input.

 

Those are excellant heads. I have been thinking about this and I just don't know without upgrading the exhaust. Did some compression calculations using the GM .028 head gasket and I came up with 10.18:1 compression which is not to bad with the stock lower end. So if you were to use one of the new high lift cams such as the Comp Cams 218 and good valve train componets you might get away with it and with some decent perfomance. But you really need to upgrade the exhaust and catback and then you will be cooking. Then upgrade the intake system and you will be smoking the tires to no end.

 

200 cc runners are too big, and port velocity, at lower engine speed would suffer. Way overkill for a TPI. You would never see the RPM range, where those heads come to life, with a TPI.

 

I defer to MadMax and his 195cc AFR's and the stock TPI runners. 331RWHP with an automatic and XFI cam. That is what has changed my mind on the subject. I was at the club dyno tune for the witnessing along with getting my car dyno's with the current numbers.

 

I saw your sig, and your combo is almost identical to my old one a few years back. Our MPH are dead on, except my best ET was only 13.00, with a stick. I know, I know, the ET should have been better. The ZZ9 cam and TrickFlows were a great match.

Yea, he had like 1 HP on you. What was the TQ?

 

If you can get them for a really good price, $600 go for it. Its true though 200cc runners is alittle big for you application. But it would'nt be a bad choice if you were going to upgrade latter to a bigger motor or ditch the TPI.

 

I don't recall what his torque was but it was higher than mine. Mine is at 370RWTQ which works out to about 460tq at the motor. However my torque curve is pretty flat like an LS1.

 

331.6hp, 379.9tq.
More on both counts. AFR seemed fine, didnt do any tuning at all. I may have been able to pick up another 5 or so like everyone else did that day if I had wasted any time with it. Cant wait to see what it does with those factory dented up runners gone.

Oh, they are AFR 190's, not 195. Ported (specs hiding somewhere) and cut to 60cc, for 10:1 compression on the button.

As for low RPM power, I really wish I could tell you that. Stupid trans was having attitude and we didnt get any decent lower RPM runs. So your guess is as good as mine. It smokes the 245's off idle with ease though. Even burns up ET streets at the track. Friggen traction issues...

 

Sounds like low end torque is not an issue. Glad you chimed in for the proper figures and your input.

 

Saw my name, figured I'd chime in since its ME you're talking about.

Flow specs as follows:
0.100 77.8, 60.4
0.200 141.8, 108.3
0.300 207.4, 150.4
0.400 246.0, 187.0
0.500 271.5, 199.8
0.600 285.2, 209.0

Cant tell you the runner CC, was not measured. I honestly didnt care. They were opened up a fair bit though, and matched to a 1206 on the intake side. Dont ask me about the exhaust flow, those are the numbers and I guess thats as good as it got.

 

They flow a tad better than my Dart 200's. When you upgrade the intake I think you will gain bigtime on the horsepower. Here are the Dart 200's going on my next rebuild. Lift then intake and then the exhaust with a pipe.

.300...209....155
.400...237....193
.500...269....216
.600...281....222

 

Well, that's the thing. I also don't want to kill mu low end torque that much. If I stayed with an aftermarket TPI system like the Super Ram, would those heads be able to give me good torque on the 350 and still come to life at the higher RPM ranges?

 

More than likely. Another member (Vincent Z28) dyno'd same day with a Super Ram, he has a 350 with a Lunati grind (226/.565 something or other) and put down almost 375hp but I dont remember the torque. I dont recall it being overly low. I think it was over 400. His is a stick though.

I dont know why people get so stuck on torque. Its a TPI, it will have torque. If you really want more, buy a diesel. No offense. Torque really should be the least of any TPI owners worries. Take mine for example, are you even hitting 380tq at the rear? I dont think so.

 

My torque seems to go up with each mod. I can break the tires loose at 45 mph by just stomping on the gas pedal. You are right Vincent's torque was just over 400 at the rear wheels something like 404. Vincent is running the Trick Flow 195 heads and the 226 degree cam as stated. He passes California smog just fine and with his dual cats. These are California smog legal cars.