I have a ported tpi setup all factory with ported l98 heads and a 52mm throttle body, fuel injectors are 24 lb, edelbrock headers and y pipe with a hallow cat and slp loudmouth cat back, t56 6 speed trans and 3.70 posi gears.Im reading that they are 58 cc heads. If i run a eagle 383 rotating assy do I need to use dish top pistons to stay under 11:1 compression so I can run pump gas?
Also i hear with the aluminum l98 heads I will need to have the valve guides cut down and spring seats widened in order to run over a .470 lift cam and bigger springs??

Lastly what cam should I run with all of the above in mind? It needs to be a hydraulic roller cam thanks - patrick

 

aluminum L98's are 58cc. Will need a -12 cc dish or bigger to keep under 11 to 1. SRP I think makes a 12cc dish or atleast a 16cc dish. One of those will work great on 93 oct with a big enough cam.

Yes, cut the guide bosses down to allow more retainer to guide boss clearance to run over .470" lift.

Dont need wider pockets since you can get a nice small diameter double spring to handle hyd rollers that will fit in stock seat pockets. 1.27-1.29" diameter springs like patriot extreme gold, afr 8019 springs, and a few PSI/PAC springs out there that will work great.

Or you can run a PAC 1218 or 1518 beehive. great springs too.

383 TPI wont need alot of cam due to short rpm range. 224 deg duration on the intake would work. Something like the comp cams cc503 grind which is the 276HR but on a 112 lsa. That would do it. 268XFi is a touch small but would work great too. 280xfi is abit large for the heads/TPI but could work too if you run closer to 11 to 1 compression. Need larger cam to bleed off cylinder pressure to run on pump gas when running closer to 11 to 1. I'd try to run 16cc dish and ~10.5 to 1 comp.

Got alot of cam choices really.... LPE 219 cam would work ok but its better suited for better intake/exhaust flow ratio heads like LPE's cnc ported L98 heads

Or you can go custom grind from one of the many great cam guys out there.

In general, lower 10's to 1 compression should try 218-224 deg on intake at .050". 6-8 deg split would work for exhaust side. Closer to 11 to 1 comp needs closer to 230 deg intake to help lower dynamic compression, or atleast a 224 on a tighter LSA. Just my opinion

 

Thanks very much!
I just found some speed pro h859cp30 hyperutechnic 12 cc pistons for 160$ not bad since im also saving for a t56 lol also springs seem readily available as well .
Im going to look around now at camshafts now with price in mind what lift would you go with along with the 224 intake ? I have previously run a .454/.468
256/268 duration lunati voodoo cam that ran well with the tpi

 

Assuming a roller block like factory L98's? Those heads will flow to .500, so to maximize that I'd stick around .520-.550"