IrocSS85

Im getting them used for a good price. If I was geting new ones, Id get the afr's. but, my question is what push rods do I need? I see on summits site that it requires custom length pushrods. but it doesnt mention what kind to get. any ideas?
also, which head gaskets do I need to use since its alum.? I use head shims now, to keep my compress. so Id like to do that if poss.. any comments about that? Ive never had nice heads before much less alum. ones, so I dont know if I can do that.
T.I.A.
chris

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1985 Iroc Z, (parting out, email for parts)

1986 Iroc Z
355, ported camel hump heads,750 holley, 700r4, 10.5 compr., forged flat tops, solidcam .501I .510E, 4gen rear w/3:73 posi, girdle, and disc's, Edel. torker II, shift kit, 3500 stal, hedmann LT. headers, 4 gen seats, man. strg., lt1 starter, alum. w/p, msd 6al, coil, dist., mallory wires. mid 13's for now. lots to play w/still

1995 z28,SS Hood, Iroc style spoiler, tints and black outs, 700r4,2400 act. stall speed,B&M hammer shifter, 17" budnick trilogy III wheels, 275/40 ZR17, 160 stat, man. cooling fan sw., homemaid CAI,1LE elbow, hypertech airfoil, t.b.bypass,!cat, flowmaster, !maf screen, relocated batt., 1LE front l.c.a.s', poly trans and torq.arm bushings, MSD 6AL, custom program, p&p maf, accel coil, and under drive pulley

mods that i have, just not on car yet:
msd wires, edelbrock mid. headers, edelbrock rpm catback

GMTech

I have the G1 heads, which are the older versions of the G2 heads. You WILL need custom pushrods, but alot of it depends on what cam (i.e. roller, flat tappet, etc...) and sometimes what rockers you are using (TFS says different rockers use different pushrods). I have the G2 instruction manual, but your best bet is to get an adjustable pushrod to check your valvtrain geometry.

As for gaskets, I used GM P/N 10105117 gaskets, since they are safe to use w/ aluminum heads and have a compressed thickness of .029" I also used the reccomended ARP head bolts, and APR thread sealer. I also used Trick Flow Roller rockers to clear the large springs (I have the upgraded springs), but its not neccasary.

One word of caution, what cam are you using? Due to the "twisted wedge" design of these heads, you have to be careful that cam you run. The large 2.02 valve and the angle at which it sits makes the Piston to Valve clearance much closer than stock and certain lifts require custom pistons.

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Webmaster:SETHIRDGEN
GM Tech
ASE Master Auto Technician + L1
1987 Trans Am: 357ci
Ported TFS heads, ZZ4 cam, headers & exhuast and other go fast goodies
13.53 @ 103.77

IrocSS85

I was afraid of the piston/valve clearance issue. I have solid flat tappet .510 cam in there now. what lift do you think I can get away w/? I have the typical trw 2256 forged 4 brow pistons.
you mean the trick flow roller rockers arent tottally nec.? or the springs? Im in debate now if I shoujld get a roller mechanical cam now or wait. I'll prolly test fit the head and see how much clearance I have w/the .029 gaskets.
how much compression do you think I'll lose w/the thicker head gasket? far as I can tell, proly around .3 or so cause I read that the .015 shims give around .5.

what do you recomend I do to the ports of these heads? anything? I dont want to hog them out or anything, but I fig. i can match them and clean up around the short turn (pocket). how much did yours flow after porting? just curious. thanks for the heads up though. chris

GMTech

Your cam is pretty much at the limit, depending on the springs installed. Are your spings single, or double? (The single sprigs have two: a sping and a dampner, the double springs actually have three, two springs and a dampner). The single springs are claimed to only take .501" of lift, and the double is claimed to take .600", However, when I talked to Artie at TFS, I think I remember him saying thats to allow a large safety margin, and the single would work w/ my .510" ZZ4 cam... Find out what you have though to be sure.

As for the P/V clearance, I seem to remember .520"? maybe being the max before special pistons needed. Best thing to do is to check. When I checked mine w/ the ZZ4 cam, I had plenty, but my pistons have a slight dish w/ 4VR so I had plenty of room to spare... If you have flat-tops, definatly want to check it out...

I ran my engine combo on the compression calculator using both thicknesses, and you are right, about a .3 loss going from the .015 to the .028 (I said .029" earlier, its actually .028" )

TFS claims in the instruction packet that OEM stamped steel rockers will work, but as cheap as RR are, why not throw down for some... I bought my TFS rockers from summit for like $210, and there are others that are cheaper than that...

Definatly clean up the ports, however, mine are flat out hogged. Here is a pic:
http://sethirdgen.org/images/TFS1.jpg

TFS states w/ a flatt tappet cam, your pushrods will be in the 8.700" range, but like I said, its best to get an adjustable and mock it up to be sure. If you color the end of the valvestem w/ a black marker, install the rocker and turn the engine over a few times, by looking at the "rubbed off" spot, you can see if your in the ball park or not...

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Webmaster:SETHIRDGEN
GM Tech
ASE Master Auto Technician + L1
1987 Trans Am: 357ci
Ported TFS heads, ZZ4 cam, headers & exhuast and other go fast goodies
13.53 @ 103.77

GMTech

Oh yeah, and MAKE SURE THEY ARE G2 HEADS! Alot of people like to claim there G1 heads as G2, since they are more desirable. You can tell the difference by the guide plates. If the guide plates are flat like standard SBC guide plates, they are G2 heads. If they are twisted, like BBC plates, they are G1's. Hope this helps...

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Webmaster:SETHIRDGEN
GM Tech
ASE Master Auto Technician + L1
1987 Trans Am: 357ci
Ported TFS heads, ZZ4 cam, headers & exhuast and other go fast goodies
13.53 @ 103.77

IrocSS85

thanks for everything. sending you a long email w/more questions. chris

GMTech

No Problem.

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Webmaster:SETHIRDGEN
GM Tech
ASE Master Auto Technician + L1
1987 Trans Am: 357ci
Ported TFS heads, ZZ4 cam, headers & exhuast and other go fast goodies
13.53 @ 103.77