1991z28L98

iTrader: (1)

I have a 91z28 with a stock l98 I have the opportunity to buy a set of Dart iron eagle heads cheap new but they are blem heads so 58cc instead of factory 49cc this is good that should put me at around 10.8.1 compression by my numbers only problem is there not vortec heads but i have a non vortec base intake for tpi im on a budget so the induction system will have to wait for now its stock bottom end the dart heads if its worth it new roller cam heads built to match and basically stock tpi until i can afford otherwise reprogram of the prom witch the car has an upgraded one already not sure its specs is it worth changing to non vortec?

TTOP350

iTrader: (8)

A quick tired Tony edit of your post is below...
Hope this is what your meaning and helps whoever wants to answer...
I believe factory is a 70ish cc chamber?!?!?! help?

I have a 91z28 with a stock l98. I have the opportunity to buy a set of Dart iron eagle heads, cheap. New but they are blem heads so 58cc instead of the factory 49cc. Is this good? That should put me at around 10.8.1 compression by my numbers. Only problem is they're not vortec heads. I have a non vortec base intake for tpi. Im on a budget so the induction system will have to wait for now. Its a stock bottom end with dart heads. If its worth it? New roller cam heads built to match and basically stock tpi, until i can afford a reprogram of the prom, witch the car has an upgraded one already. Not sure of its specs is it worth changing to non vortec?

1991z28L98

iTrader: (1)

factory 1991 l98camaro heads are 64cc the dart heads are 58cc and flow much much better i just want to know if its worth it over the vortec heads and. TPI system IE: lower intake runners and penlum are stock i will have to get the prom re-programed anyway because of the new heads cam and bigger injectors i said it right the fist time i just want to know if its worth swaping to the non vortec heads.

dspencer24

iTrader: (3)

So you have a non vortec lower intake? sounds to me like a done deal. The vortec stuff isnt all that great as far as flow goes and cost more money unless you get it used. Although 10.8 on iron heads what cam size cam are you running by the way if its not big enough you might run into problems

Also whats with the vortec heads are you dead set on using them?

1991z28L98

iTrader: (1)

Alright thats what i was leaning to just wanted someone to agree with me i have book smarts but when it comes to hands on i haven't done alot. and as far as the cam im not sure any advise a street strip cam roller of course i like the Big mother Thumper from comp cams but idk if thats big enough someone give me some ideas and links or part numbers....

dspencer24

iTrader: (3)

Well you dont want to big and you generally want to stay in the 112-114 lsa area for tpi. I would def call crower and comp cams and some other cam companys and talk with them a little bit, they will be able to give you the answer that your looking for. Be careful though running that high of compression on iron heads and finding a cam to match you will need bigger injectors/afpr most likely and tune.

1991z28L98

iTrader: (1)

I'm accounting for the injectors and a reprogram the cam is what has me stumped i want a good street strip cam but im not sure with roller cams its new to me...

dhirocz

iTrader: (2)

Vortec heads are great heads, but unless you know how to do the work they need to make them right (cut spring pockets, spot face the guides to fit better seals lower for seal to retainer clearance, valve job, resurface, magnaflux, remove rocker studs, spot face and tap for screw in studs, drill out pushrod guide holes) and then port the head to open up the pushrod pinch, you are better off going with the Dart heads. I could have easily bought a nice set of heads for what I paid in heads/valves/tools and that doesn't count my port work. I've run Dart heads, they are my preference in an aftermarket street head. This time I chose the vortecs so I could outfit my toolbox so I could do them later on cheaper if I chose to, since I like to use the Vortec 350/LT1/Gen VI BBC as a basis for engine building. Not to mention I have like 6 sets of heads and 8 engines lol...

I just finished a 383 TPI with Vortec heads on it. If I had to do it again, and I didn't care about tooling, I would just go to an aluminum head like the E-tec or iron like the RHS Vortec or GM large port Vortec and call it a day. Took lots of work in the intake runners to open them up halfway decent. I think they are best left to the 305 and mild 350 TPI cars. The intake took tons of work too, and I'm still not satisfied with it. Vortec heads start hurting VE at 3800ish RPM on a 350, just after the stock torque peak. They are very efficient though, and produce great torque, and for that alone, I like them.

1991z28L98

iTrader: (1)

dart heads it is now for help with the cam any suggestions????

dspencer24

iTrader: (3)

i would look at the xfi 268 but you have to get your heads set up for high lift. LIke I said call one of the cam companys I have called crower, comp cams, mike jones cams, and one other. They were able to tell me what cam i was able to use for high compression and pump gas. Im running a crower cam 221/230 114 lsa and i have a little over 10.8 to 1 compression. and i should be fine on 91 oct pump gas.

SMKNIROCZ28

I dont know if this helps but if you do go with the vortec heads you should look at the vortec manifold from SDPC. bolt right on it states. heres the part number

Part Number:
SD3816


Brand:
Scoggin Dickey Parts Center


SKU: SD3816

dhirocz

iTrader: (2)

Are you staying long tube runner?

If so forget those big cams. Any cam that is lopey is too big for a TPI engine. Even a cam with a noticeable idle is pushing it. My 383 isles smooth at 750, and I wouldn't go bigger than the 218/224 duration cam in there now.

Generally a mild or stock 305 or 350 TPI can take an LT1 cam as an upgrade, with it helping more on the 305. I noticed nothing more than off idle improvement and smoothness in my 350 TPI with an LT1 cam. The 350 can take anything from a 210/218 to a 214/220 without risk of the cam being too big for the long tube runners. A 383 can take up to a 218/224. Can you go bigger? Yes. But you better know what you are doing. Cams bigger than that are generally too big for a tuned port unless you make quite a few changes.

Low buck? LT1 cam, LS7 liters, the dart heads, cleaned up stock base and long tube runners. Put exhaust on it too. Or go aftermarket with the cam and get some slp runners.