see i have a 1998 trans am and i was woundering if this set up would work they say 1999 and up but i dont see the difference in the two
please help thanks joe

SLP / AFR Cylinder Head & Cam Package, 1999-05 402 CID LS/LS2 600 HP

Save Money on this SLP AFR Cylinder Head and Cam Package

We teamed up with AFR to bring you these street/strip heads and matched them with one of our high performance LS1/LS2/LS6 cams for an even better deal. The heads flow enough air (up to 320 CFM intake) to keep up with our ZL402 engines but they work with all LS1, LS2 or LS6 small blocks as large as 427 cubic inches. The secret to the high flow numbers are CNC porting and a newly designed combustion chamber with a double quench pad area.
Another reason we picked these heads is the rugged design that can live on top of a high-power engine. Don’t worry if you use nitrous or a blower because AFR’s 3/4 inch-thick deck is standard, along with reinforced rocker stud bosses, thick-wall runners and interlocking ductile iron valve seats. To maximize performance, we include double springs (.600 inch max lift) and titanium retainers.
To really get the full potential of these heads we matched them to our most aggressive cam for larger displacement engines.

Camshaft Specs: Valve Lift Duration@.050
in: .596" 250º
ex: .596" 246º


Centerline - 114º
Lobe Separation - 114º

Best of all, you’ll save $25 over the cost of purchasing the parts separately!

NOTES: These heads are ready to bolt on, but we recommend that final assembly of any engine be performed by an experienced, professional mechanic.

AFR SLP Cylinder Head and Cam Package features:
Intake flow up to 304 CFM at .500 lift, 320 CFM at .600 lift @ 28” of H2O.
Exhaust flow up to 250 CFM at .600 lift @ 28” of H2O (using 1-7/8 inch exhaust pipe).
225cc heads with 62cc combustion chamber.
CNC ported intake and exhaust ports, and combustion chambers.
2.080 intake, 1.600 exhaust standard length valves.
3-angle radiused valve job.
7° titanium retainers and valve locks.
1.290 inch double springs, 135 lbs seat, .600 inch maximum lift.
Fully assembled heads ready to bolt-on.
Matched .596”/250º int. .596”/246º exh. camshaft.

http://www.lmperformance.com/5916/1.html

thanks again joe

 

probably the reason why it is 99 and up is because it is meant for a 402 and not a 346 like a standard LS1 is. Even if that reasoning is incorrect, the best bet is to email them and ask if it works for a 98 and if it doesn't then ask them what does.

 

It says it fits all LS1's and will support up to 427 cubes. It sounds like this package is optimized for a displacement larger than 346 whereas it will still work on a stock block. That cam is enormous at 250 intake/246 exhaust. A larger displacement motor would eat up that cam much easier than a 346.

 

This is topic for debate in the Internal section.

 

well one diff is the 98 has perimiter head bolt style and the 99+ has the center head bolt style.

 

thanks guys if for your help i think i will email because i was looking to buy these cause i just bought a d1 procharger so if some one knows if it will work then tell and if one of you know a set up that will put around the 600 or up in horsepower and torque then tell me what will work for a round $2000 or $3000 or cheaper if possiable
thanks joe

 

Go with truck heads.

 

will that put out the kind of power i am looking for and if so what kind
thanks joe