TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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i know they are not great heads but how much could i gain with aftermarket heads.. its been bothering me for a while and i want these stockers off my block.... i have such a great shortblock, cam and maxed out tpi that i feel like i kinda ruined it with these unported stockers.. i cant beleive i put these heads on my build... i didnt have the money for aftermarket heads and im saving now and will be doing my own head swap.... the engine does feel alot stronger than my old l98 but im just thinking im holding so much power back with l98 iron heads....
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I have read both. They are ok, and can be made to flow well, to they are boat anchors. I have an extra set and I was shocked how horrible the casting in the bowl is, and the valves are just horrible as well. I have a local shop that is going to re cut the valves bigger and with back cut 3 angle valves with all necessary work. Bead blast, magnaflux, deck cut and install valves for just under $400, I have a friend that is teaching me how to port, we will see if it helps when I am done. But it is no wonder that they flow like crap out of the box.
When I first looked at them it seemed like GM was not even trying.
my heads still have the stock valves and everything.... they have no headwork done at all besides springs to handle the gm hotcam and a valve job... its like my heads are keeping my setup from what its truly capable of... dont get me wrong its strong but all the power is in the heads..... afrs are the best.. if i put those on, i could only imagine what the gains would be...
Afr claims +75hp over stock l98 heads. If you buy new heads they are the only ones I would go with, otherwise work on your stock heads. Pro1 or others may be better in a race application, but for a 180 head I would stick with the afr’s I just don’t have $1400
i will have the 1400 by jan... wow are you serious 75 plus horsepower.... im pretty sure im putting down 260-280whp now...... that would really wake up my build....
Your car is a "12 Second daily Driver GTA" and it has the stock heads? That sounds pretty damn good to me. I was thinking about the LT4 hot cam with the stock heads to save money but I thought I read it wouldnt work. Now you give me hope.
yea it should be with all the suspension/chassis/engine/tranny/weight reduction work that ive done...i literally have almost 3 pages worth of mods done to this car.... its a brand new built engine and built transmisson.... its not slow by any means... my 0-60 time is just a tad over 5 seconds....its just i want to get rid of the factory heads and replace them with much better ones... the heads are the only "factory" part that is on my engine right now...
I got a set of ZZ4 heads (Read 113 casting L98 Vette heads) for my TPI setup. I got them off ebay for $500. They flow 245CFM at the lift your using and they are a bolt in replacement for your factory heads. Just in case you were thinking of the poor flow that the 113s were usually accused of. I learned that GM kept the casting of the 113s around for its ZZ4 engine, and that they did extra work to them to help bring in more flow. And I have the pictures to prove it! They also come with LT4 valvesprings (GM's matched spring for your camshaft) screw in studs and D-shaped exhaust ports that flow more than your factory L98 heads intake ports. Top that off with 58cc chambers and 160cc intake runners, talk about torque.
And for $500 lightly used, I mean come on. I dont know about you, but im not made of money.
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2nd Marine Air Wing 3rd Gener, Cherry Point NC. Semper FI
Afr claims +75hp over stock l98 heads. If you buy new heads they are the only ones I would go with, otherwise work on your stock heads. Pro1 or others may be better in a race application, but for a 180 head I would stick with the afr’s I just don’t have $1400
What a crock of ****, another one under the advertising spell. There are many good quality heads out there and depending on what you can make better power than AFRs or not.
Afr claims +75hp over stock l98 heads. If you buy new heads they are the only ones I would go with, otherwise work on your stock heads. Pro1 or others may be better in a race application, but for a 180 head I would stick with the afr’s I just don’t have $1400
Yea ive seen that 75hp claim but you have to read that carefully. 75hp over stock l98 HEADS. if it said 75 hp+ on a stock l98 motor then ide be impressed. Not knowing what motor they tested that on for all you know that could have been on a radical +400 ci SBC. In which case 75 hp isnt really such a fantastic gain since the stock l98s wouldn't have been up to the task anyways. You also have to consider at what RPM? Again if the built a a 8k rpm large displacement sbc again the factory l98s wouldn't be up to the task and who can really run at those kinds of RPMs anyways? Theres alot to thoes kinds of advertising claims and before you take any of those numbers with any kind of seriousness i would look at under what circumstances that test was performed. Not saying there bad heads just i feel that advertisement was a little dissipative. On a side note the heads ide use are GM bowtie vortec heads. There basically an even better high performance version of an already great flowing head an advancement beyond factory vortec heads which outflow many older style heads right out of the box. Something like that would be hard to beat especially considering there roughly $700 for an assembled pair.
