I apologize if this isnt truely advanced,Mod's feel free to move it if need be.

OK,i am going to build a 6" rod 383 nitrous setup. It will be a solid roller,and will be a direct port setup.

My main question is,what would be the Pro's and Con's of these 3 heads for this type of setup? I will be aiming for around 11.5:1 compression,and cam will be chosen after the heads.

Would there be much advantage to running the 220's or 227's over the 210's i am kind of leaning towards now? I know this isnt a greatly detailed post,and if you need more info please ask me.
Would the 220 or 227 lose too much velocity? 210 and 220 are the heads im most interested in,seeing how they will work better with the LT4 intake.

 

personally i went with 220cc AFR heads because i suggested to Craig@GTP that i need heads for a vortech YS-trim blown 396 LT1 and told him i want no less than 320cfm intake with good port velocity i suggested 210cc, 220c and 227cc AFR's and he told me the 220cc will be the most suitable heads for my blown 396 and they will be easier to get the cfm required. i told him why not to go with 227cc heads he told me they are too big and 220cc heads will be easier to get 320 cfm than 210cc heads. he also told me that i only need his stage 2 porting for the 220cc heads that will make good port velocity and high flow numbers where stage 3 will require more cam and more gears and higher rpm and more boost becuase they will peak higher and i will loose torque with them so i just went with stage 2 AFR 220cc. i don't know but maybe for your NA/Nitrous 383 project you only need 210cc heads but i could be wrong you might want to ask Craig@GTP. if you know Kurts he did 210cc LT4 AFR heads by Craig@GTP and they did 306cfm/224cfm at the peak with 206cc runner ( because all 210cc,220cc,227cc heads have way smaller runner volume bare with no porting) and these numbers were verified by another flowbench.

 

Not much difference between the 210 and 220... just port volume. The 227 uses the 60/40 valve spacing (larger valves) but it'll work with standard stud-mount rocker arms so that's a plus I guess.
I would look at it like this... if I were buying a set of heads to just take out of the box and go (no porting) I'd go with the 220's. If I was prepared to do a little refining, I'd go with the 210's and get just about the same numbers as the 220's by taking material out of the right places. You'd also have better port velocity and an engine that makes a little flatter torque curve.
The 227's I'd save for a big bore motor (4.125 or larger).

Best of luck.
-Mindgame

 

Thanx for the replies guys,keep em coming. Right now i am looking for an out of the box head,gonna be spending enough for the initial cost for now. Plus if i ever decide to do more,the heads can always be worked afterwards.

Wouldnt the 220's move the power curve higher in the rpm range? As of now,i will be using the stock pcm,with LT1 edit,and if we DONT go on strike,i will go to DFI. So rpm's wil be limited to 7k for a short while.

If if wont make much difference,i might still go with the 220's over the 210's......just trying to get as much advice as i can.

 

I went with the 210's as suggested by Craig at GTP for my 396 solid roller setup. I got the stage II porting, plus I run a shot through it. Compression is 12.1

I'm thinking the 210's whould be perfect for your combo. There's pictures is my sig of the heads from GTP if you'd like to look at them?

 

PNYKILR, do you have track and/or dyno numbers for your GTP stage 2 210cc AFR heads with your solid roller 396?

 

Not yet. The motor is being put together right now. Should be in the car in two weeks. as so as it's broken in I'll post the results. I know you were worried about you head choise, but I feel you went the right way, plus your SC, and feel comforable you'll reach your goals. Having a 9 second daily driven car will be nice, and I hope to be there aswell. Being that I'm a m6 car, Low ten's should be in my future on the spary.

 

What did that crank set you back? If you don't mind me askin.

 

If refering to me? I think it was $700 or $800. I'll ask my engine builder, he told me once already just forgot.