113 heads and xfi 268 stock tpi?
 

I know the 113 heads are not much better than the iron l98 heads but i can get a set pretty cheap and they should bump the compresion up a it right? And they are capable of running a higher lift camshaft without any machine work.

Im thinking of going with a set of 1 3/4" shortys and a Xfi 268 or maybe even Xfi 280. For now Im going to keep the Tpi stock untill I get some runners and port the plenum and base..

Would this be a decent street engine? NOt looking for killer numbers but want a slight lopey idle and atleast LT1 power level.

What size injectors should i use and what should I set the fuel pressure at?

Thanks

Re: 113 heads and xfi 268 stock tpi?
 

That cam is good for a strong TPI setup. Added power from increase in compression ratio won't be that much, maybe 10hp. How much are you getting heads for? I would look for an aftermarket set of heads to take advantage of cam and ported intake. You could have heads mildly ported though. Are they ZZ4 heads? Those would be good.

I came across this https://www.thirdgen.org/forums/tech...heads-how.html
I agree, it's not worth the swap. Not only will there be very little power gain, but your EGR system won't work any more (113 heads don't have exhaust crossover passages). And the intake bolt pattern isn't the same as your 87-up heads (Vette/113 heads use the earlier 86-down intake bolt pattern).

Re: 113 heads and xfi 268 stock tpi?
 

What are the specs on the 268 cam?

Re: 113 heads and xfi 268 stock tpi?
 

You're going to need bigger springs. I have that cam and it's .576/.570 with 1.6 rockers.

Re: 113 heads and xfi 268 stock tpi?
 

An original 113 head is not capable of anymore lift than 083 castings. If not modified dont exceed .470 lift.

Re: 113 heads and xfi 268 stock tpi?
 

how much hp are you looking to run?

Re: 113 heads and xfi 268 stock tpi?
 

Stock unported 113's i think the 268 cam is abit much for those heads. Unless you ran 1.5 rockers to keep lift down I dont see a big gain in the big lift numbers on that cam. I think the XE version of that cam would be better suited with 113 heads.

They will need machined to handle the lift tho. Not much work, just drilled the guide bosses down and should look into screw in studs if not already have them. Dont remember if 113's had the screw in's from factory or not.

That duration is fine with stock TPI for now and will really pick up with aftermarket/ported stuff.

That cam with aftermarket TPI will definately put you in or past Stock/bolt on LT1 territory and even stock LS1/auto range. My 99 trans am only ran 13.4's at 104mph in decent air bone stock. My HSR/full bolt on L98 was able to match that in similar air conditions and beat that in better air conditions. Cam swap would help more

Re: 113 heads and xfi 268 stock tpi?
 

well that sucks i thought those heads could handle more lift..

Im looking for around 300hp for now.
I have been reading alot and I might go with the procomp 200cc heads (or 210 i dont remember what they are) I know there not great but for $650 shipped assembled i cant even get close to that with anything else. Even vortecs will requre machine work and a new manifold so there not as cheap as they seem.
I figure with the procomp heads even though there not that great would probly push me over the 300 rwhp range with a good cam. And probly get 350hp with intake at the wheel.

Re: 113 heads and xfi 268 stock tpi?
 

Probably going to be cheap quality junk heads that may or may not work. I cant speak from any experience on this but just going by hearsay. 650 for a pair of new heads seems to good to be true and those situations usually are the case.

Some have used Skip White's freedom series heads by Patriot which i believe are 800-900 assembled. 190cc which are much better suited for a 350 motor.

Re: 113 heads and xfi 268 stock tpi?
 

https://www.patriot-performance.com/...&cat=40&page=1

these the ones your talking about? Are these aluminum? thats a good price



The vortecs are $100 cheaper but thenI would need a $250 intake base. Witch ones would be better u think?

Here are the vortecs https://www.patriot-performance.com/...&cat=40&page=1

Re: 113 heads and xfi 268 stock tpi?
 

For your goals it doesnt really matter which head. Just depends if you want a vortec intake. I would get a normal head tho since more available intakes

Re: 113 heads and xfi 268 stock tpi?
 

yes those are aluminum.

Re: 113 heads and xfi 268 stock tpi?
 

Im also going with the 268xfi for my l98 build.
Im excited would love to hang with or beat an ls1
great thread,thx for info Orr89RocZ.

Re: 113 heads and xfi 268 stock tpi?
 

I believe Skip White now prefers the Procomp over the Patriot. He lists the 210 cc on Ebay, but does carry the 190.

Re: 113 heads and xfi 268 stock tpi?
 

I would get the 190's, 210's are too big for a standard small block, 383 would be ok for 210's....but procomps usually need porting....they are good heads, but kinda have crappy casting in the runners and in the pockets. I have them and they flow great on the bench...but have 60hrs porting.

I also have that same cam....it's pretty large, real lopey, great on the top end. You need to run the beehive springs with it. The procomp heads will run these, but make sure you get .100 longer valves, and you'll also need spring seats that comp sells. You'll also need programming to get the best performance.
Great cam though, LOVE IT!!!

Oh, you'll probably need more air flow, consider upgrading your intake, the cam works good 2500rpm and up. Spin mine to 6800rpm, and no power drop off.

Re: 113 heads and xfi 268 stock tpi?
 

"I also have that same cam....it's pretty large, real lopey, great on the top end. You need to run the beehive springs with it. The procomp heads will run these, but make sure you get .100 longer valves, and you'll also need spring seats that comp sells. You'll also need programming to get the best performance.
Great cam though, LOVE IT!!!"


Your sig lists the 280XFI cam...are you running the 280XFI? I am considering swapping the 268XFI I have now for the 280XFI; wanted to know how it behaves in a 350 cu. in. motor

Re: 113 heads and xfi 268 stock tpi?
 

"I am considering swapping the 268XFI I have now for the 280XFI; wanted to know how it behaves in a 350 cu. in. motor"

Vincent should have his motor up and running pretty soon. He has the 280XFI camshaft. A report should not be to far off.

Re: 113 heads and xfi 268 stock tpi?
 

LT1 guys say it makes as much if not more power than the CC306 and is more streetable

I think its a big cam for a 350 but certainly not huge and unstreetable.

Re: 113 heads and xfi 268 stock tpi?
 

Short memories around here...

Re: 113 heads and xfi 268 stock tpi?
 

Thanx!
Thanx!

What was the question........?

Re: 113 heads and xfi 268 stock tpi?
 

I think it comes down to how good of a tuner you are and how much you can handle with a cammed up motor. Everyone has different definitions of whats streetable

Re: 113 heads and xfi 268 stock tpi?
 

true....and I do have the 280xfi. which is .570/.576 lift 230/236 2000-6000rpm (my cam card is .571/.576). I drive it on street on weekends. It's a bit much, but for sure driveable. I would go with the 268 if you're running a stock or close to stock intake.
the 268 is .570/.565 218/224 at 050. 1800-5800rpm and needs good exhaust and chip upgrade.

Re: 113 heads and xfi 268 stock tpi?
 

Been running that cam for almost 5 years now.

Re: 113 heads and xfi 268 stock tpi?
 

I picked the comp 268 xfi,Should be done sometime this month.heres The set up
Vortec 350 4 bolt main
comp cam 268 XFI Roller
comp magnum roller lifters
L98 Iron heads 64cc screw in studs
Comp 1.52 roller rockers
Comp beehive springs
Comp push rods
comp double roller timing chaing
Holley Stealth Ram
Tpis 58mm throlle body
24 lb Injectors
Harris stage 2 chip
flowtech headers and y pipe
borla cat back (no cats)

I have no idea how its gona run,or the numbers it will make. Im curiouse about how the l98 head will perform.any input is greatly appreciated thx.