Looking for opinions.

1993 Z28 T56.

383, fully forged, custom cam, over .600 lift intake and exhaust, ATI D1, NX Direct Port, Accell DFI, basically all I need to buy are heads, well that and work on the fuel system some..


Im ordering AFR's, but I cant seem to figure out what I should get. I want compression to be at 9:1 or lower, so the bigger CC chambers are a must. I was looking at the big boy 227's, but Ive heard from alot of people that this would be overkill for the motor Ive built.

I was thinking race ported 220's or 210's. Big decision, alot of money so I wanted to get some advise from you guys.


This will primarily be a street vehicle BTW, ac, full interior, ect ect. Im not a big track racer.

Any opinions, or any of you tried and have comments on different heads?

Thanks..
James

 

The main difference between the 210's and 220's has to do with the intake pushrod location. The 220 moves the pushrod away from the port and straightens the port, whereas the 210 leaves the pushrod in the stock location. The straighter port looks much nicer and gets rid of the pushrod bottleneck of the stock head. Theoretically, the pushrod being moved over will only require that the rocker arm sit at a little bit of an angle, but this moves the rocker stud a little, so regular stud girdles will not fit. I've heard, however, that the 220 valvetrain geometry is harder to get right and you may need 2 different pushrod lengths for intake versus exhaust.

Mike

 

Mike if you talk to AFR they will recommend shaft rockers with the proper offset. Its not mentioned on their website or in literature but thats the justs about it. I have tried the 220s and even used a set of two peice guide plates which helps to align the push rods but even that isn't right. As the rocker is cocked and will cause a weird wear pattern on the valve tip to indicate that the geometry isn't quite right.

I am currently running their CNC 210s with additional port work. They flow as well or better than their 220s. Plus another tidbit, the 210 and the 220 exhaust flows the same so even if you get a little more on the intake side, its not going to exhaust any better on the exhaust side, so thats the restriction unless you port them more.

 

I run pretty much the same combo on my 355 with regular 210's. Like stated before they both have the same exhaust port..........

 

Ttt