My l98 iron heads got a 3 angle valve job, ported, performance springs, roller rockers, and new valves. Would I be able to get into the high 12's with these heads along with the right combination of everthing else it woud take to get my best time? Or has anyone ever heard of someone making it into the twelves with l98 heads on a N/A motor? Just curious since it is going to be another month or two before I see for myself.

 

Yes you can get into the 12s. Just dont mismatch the parts, buy parts that work well togeather.

 

how ported are they? the more the merrier.

there has been LT1 cars with heads that flow 220 or so cfm make high 11's. lots in the 12's full weight

mild cleanup on a L98 head should be near the 220 range i would think from what i seen in one thread about porting L98 heads.

i hope to be mid high 12's with a LT4 hotcam or comp cams 503 224/230 grind on my HSR l98 with cleaned up l98 heads...not really porting them out too much

 

I am not really sure what they flow but I might be able to find out. The bill from the mechanic just says that they where given a performance 3 angle valve job with stainless steel valves, performance springs, port bowls and flow bench matched. My mechanic said that he was impressed with the heads but I guess that might not mean too much. Iam using the zz9 cam from tpis along with there miniram. edelbrock headers, block bored .30 over, forged pistons with a compression 9.5:1. I will see if I can find some info on what l98 heads can flow.

 

sounds like you could be near 300 whp and that will go 12's easy. just needs good gear/converter/sticky tires

 

Yea I was thinking 3.90 gears with a 2400 stall and full slicks. Also after I put some miles on the knew engine I want to use NOS to put me into the 11's.

 

might go alittle more stall but 3.90 gears should help it move.

 

you can go high 12s with stock l98 heads. Mine havent been off the block yet. I have a miniram, zz-409 cam, valvesprings for the cam, vig 3200 stall, and every bolt-on including full exhaust. Other than the springs, the heads are stock. I went 12.90 at 106. I would think that ported heads could do easy mid 12s.

 

thats good to hear. i plan on a hotcam or similar size cam swap with mildly ported stock heads just to see what i can get. i want mid high 12's. But the way it looks, the cam will have to wait for a while. 3.73's might be next tho

 

What do the heads flow? This is important info for some of us. Please, if you got the numbers, POST 'EM!
Thanx, Morgan

 

I dont know if the gears are hurting you that bad to go through all the trouble.

A LT4 HOTcam with 1.5RR's and comp 981 springs with LT4 retainers will give you a HUGE boost.

LT4 HOT cam $175
981's are like, $65 and require no machinework to fit and coilbind at .525" Which is what the LT4 specs out at 1.6 ratio.
LT4 retainers are cheap and lightweight. Like, under $40 I think for a set of 16. I had like, $100 in my spring/retainer upgrade and I lost ALOT of weight out of the valvetrain.

$350 for rockers for comp pro-magnums? Those arent even needed, but would help some.

 

i hear that the retainer hits the guide boss or something like that at .480 lift so even if i had new springs for .550 lift it wouldnt matter, it still hit at .480. So they say to shim the valves up and use .050 offset locks or grind down the guide boss which requires machine work and taking the heads off

But since i'd need screw in studs anyway, the heads got to come off, and might as well grind the bosses down which could add up the cost.
I could get the cam for 100 bucks and i've already got 10 degree retainers and locks, and Z28 springs (.510 lift rated) which i'd like to get rid of for some 981's or something with abit more lift for safety clearance

 

Why do you want to waste all that money in machinework and parts when a set of built trickflows are about $1000?

 

well i was trying to do this on a budget and i know my old shortblock will not like a big heads and cam upgrade for very long. And it be alot harder to tune with new heads since i'm just a beginner. now that i think about it i may go with some cheap summit aluminum heads or ZZ4's if i can find them since the cost will only be a few bucks more. if i'd go aluminum i'd need 58 cc chambers just to keep compression up. 9.3 to 1 stock ratio on aluminum heads just isnt right.


But i'd hate to buy a set of heads and have to get another set down the road for a new motor that i actually wanted to build. But we'll have to see. I dont think i'm gonna be doing this anytime soon now but its stilll early to tell

 

Hang around in the for sale section, I got my brand new trickflows for $850 with two sets of valve springs.