HeavyChevy, the only thing I am the least bit uncertain about is the intake manifold. On the street, a car like this will basically "explode" and spin like crazy anyways, I doubt anyone one even notice a difference in low end performance until they hit the track. From all that I have seen, the RPM air gap does a great job of making more average HP and TQ, so that's part of my reasoning. I'm figuring on shiftin around 6500 anyways, so I guess I'll have to look into this some more.


I can't wait to get the car going though, the transmission is now finished and I'm ordering the Spohn torque arm/crossemember assembly real soon.

 

That may be but where does you cam make power at? Where does your RPM end up everytime the gear shift occures?

 

Nate, I agree with you about the average HP/TQ results but when that converter hits once you go WOT, the engine is gonna be at or above 3k so your already half way thru the AirGap's effective range. Then you only have 2k or less of range left. Just use a single plane and be doen with it. I use a Team G w/ the 2 inch rise and it has been port matched. I love it and had no problems with it.


Another good point....CompCams says the cam's effective RPM range is 2400-6800 rpms !!! Another factor that backs up my words. If you in fact will be shifting at 6500 and using that AirGap; then you might as well go with the XS274S instead. It's rpm range is 2000-6400 rpms! But then your stall is too high...hmmm

Do what you want but if you want to get all you can out of that nice new engine of yours up TOP then you "should"use the single plane. My 3cents...

 

You know you are probably right. I'll look into the Team G (which I'm familiar with) and probably a Victor jr as well. The difference truly is negligable especially considering a possible gain of 20hp up top.


HeavyChevy,

You bring up a good point about the gearing and converter. Like I said before, I'll be in the 3000+ range immediately after going WOT, so as long as I make sufficient power to 60' well I'm not really concerned.


Single plane it is! The more I think about it, the more it makes sense.


(Even better, I'll have the money saved for those AFR heads next week. )

 

Regarding making AFR190s into 195s.... yes. That's what AFR does. They're the same casting. The only difference is that the 195s have a slightly larger intake opening to match the larger runners of the Victor Jr. intake manifold, where the 190s have an intake opening closer to stock size. No other difference. They flow identically.

Beware anyone who says they can hog out the ports and make it flow more than AFR's CNC porting. Maybe they can but I'd ask for before-and-after flow bench results. Getting modest flow improvements at the expense of velocity (much larger ports) is not usually a good trade-off.

Porting heads is all about expereince and documented results. If I was to tell you I could port a set of heads better than AFR I would be lying to you. All the easy stuff has been done on the AFRs- you have to really know what you're doing to get meaningful improvements without serious trade-off. In my humble opinion, of course.

 

I heard they are discontinuing the AFR 190's because they are to similarto the 195 and flow close to the 180.

I'm building a 'budget' performance motor, hoping to get 500 ft. lbs. out of it. I'd be happy with 475 HP as well.

heavily ported LT1 heads, converted...would have used AFR 195's but I need a small compbustion chamber. you can buy a set anf rebuild them with ss valves, springs etc for around $800ish.
ported LT1 intake...bolts rght to the heads...how convenient
undecided on cam, but most likely the GM 847 cam...need something streetable and compatible with the MAF TPI systems for now.
HT383 crate motor short block, blueprinted with HP bearings, roller chain and high-pressure pump.

Should get the top end done for roughly the price of AFR's...and the head porter (lloyd) has been known to port them to outflow AFR's out of a stock LT1 head, with stock valves.

Next motor I get will be with AFR 210's on it...400 small block.

Your 383 will have plenty of thump with that cam...I was considering the 242/248 XE cam but was worried it was too much for a stretable 383...not the 400 though.