I want to make absolutly sure about these heads before i buy a set.
Please correct me if I'm wrong.
I don't need special length pushrods.
I won't run into clearance problems with a cam around .510 lift.
They have all sensors/accessory holes in them.
They have screw-in rocker studs.
Come with valve seals.
Help me out.

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'88 RS (originally 2.8)
-350, .040 over, vette alum. L98s, stock tpi.
-305 injectors & chip
-TES headers & edelbrock cat back
-3.73 gears, 700r4.
Best with 2.8-17.4@77mph
Best with 305-15.0@93mph
Best with 356-13.7@101mph
on a 2.050 60 ft.
(Damn the 2.8!)

 

why?the l98's can be made to flow extremely well with half the money you're gonna spend on those trick flows findd a reputable shop get the valves enlarged to 2.00 intake/1.55 exhaust should give you all the volume you need next concentrate on the size of the runners keep them conservative if you are gonna go with a long runner intake(tpi)to keep the velocity high polish the chambers as well as the bowls for this a good shop shouldn't kill you on the price and they will perform better on a tpi equipped motor than the 23 degree heads due to the larger runners causing a decrease in velocity essentially changing the harmonics a tpi engine needs to make it's huge tourqe on a mild motor there is no need for big heads if you are gonna keep a stock type intake.


work smarter not harder same concept goes for engines!!!!!!

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87 trans am 350 L98 aluminum heads,LT4 hot cam,slp runners,1 5/8 headers,y-pipe,edelbrock base,hi flo cat,air foil,afpr,ported plenum,t-5 tranny w/centerforce clutch and a 3.27 9bolt(11.9in. brakes),ads strip chip,relocated iat sensor,hollowed maf

14.10@97mph w/2.01 60'
superram and chip coming soon

 

No you don't need special lengh pushrods-however I did need to get slightly different lengh for perfect valvetrain geometry due to head milling and 1.6 ratio rockers.
Clearance shouldn't be a problem, but it will depend on your piston choice-high dome = less clearance! You should always check it!
They do have all the access. holes.
They do have screw in rocker studs
They come completely assembled with seals.

I had to have mine milled to 58cc chamber for my desired compression ratio, otherwise its a bolt on-no problems.
They have angled spark plug holes-so it worked great for clearance and ease of changing them with my Hooker super-comp headers.
The Twisted Wedge Trick flow heads are the ones that can give you clearance problems due to the valve angles-not the 23deg. Trick flows.
Also the AFR's do flow a bit more but a lot more $$$!!!


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86 406

 

Thanx for the info Drive-it.
Pete, I do like the L98s, I have already had them ported, and polished the chamber and exhaust runners, they work pretty well but not as good as I hoped.
I am converting to SuperRam so I think the TFS heads will work better than the L98s.

 

Just a little perspective. Follow the head evaluation articles over the last couple of years and you'll know the 23 degree TF heads aren't huge volume runners. The articles mention things like "flow figures don't tell the whole story...". So don't take this as a flame.

The 23 degree TF heads are about the same volume & flow as the first generation TF twisted wedge heads I bought. Take the mods listed in Pete's list plus TF tw heads, then replace the LT4 hot cam with the stock L98 cam and that's literally the setup I was running 13.2-13.4's at HRP. That was better than a couple of friend's f-bodies with ported & polished L98 heads and cams done at the same time. Besides, I paid $675 for my heads and I feel they worked great with the LTR setup (Summit isn't the only place to buy TF heads, so the most commonly quoted price on the heads can be beaten some).

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KevinP92Z
92 Z28 383 SLP cam,SLP headers,SLP 2ontheLeft,Trick Flow TW heads & pistons,Edelbrock base,Accel SuperRam,52mmTB,Scat Crank & forged ConnRods,MSD 6AL,SLP convertor,Baer 13/12" Track,Moser axles,Hotchkis,Genuine GM 3.42s,SLP HD Torsen,17x9" chrome SS rims
96T/A w/SLP Ram Air,SLP 2ontheLeft, Bilsteins, Baer, Hotchkis, Genuine GM, Torsen
76 4X4 Blazer 400TPI project

 

I use a fully ported set of the 23*. You don't need special length pushrods and the springs that come with them are good to .500" lift. When in doubt about a product, ask the manufacturer.

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N/A 406, TPIS Miniram, 58mm TB, 30lbs injectors, Custom Ground Elgin Cam, Ported TFS heads, SLP 1-3/4", & DFI computer.
11.70@117mph

 

They also come with guideplates and studs, but don't come with bolts or gaskets. Use a fel-pro 1010 gasket so you don't brinnel (indent) the aluminum. The ARP bolts are really nice pieces.