90 RS running stock 305 tbi motor. previous owner had motor put in last year. compression is excellent, no smoke, no knocks. runs great. but...it will be replaced. currently building a 355. .030 over 350. comp cams xe262 cam with .470 lift, 224 duration @ .050 lift. flat top pistons. block was decked .005" to ensure dead level surface. i have decided to go the tpi route. speed density version, as i have easy access to the parts. this car is being built as more of a cruiser/mild show car. it will occassionally see 1/4 mile time, but i have no illusions of blistering speed. IF it breaks into the 13's, i'll be happy with it. (actual race car is another project, another story). so, with all that said, my question:

what is the concensus with using the stock 305 tbi heads? i've read, and read, and read, and read some more, and still not real clear. some say it'll work great, others say don't waste time. it turned into a bash me and my ride show on another forum, so now i'm here. i can take the good, the bad, and the ugly, but when it strays from the actual discussion, i tend to leave it.

i have access to a great machine shop that is awesome at cutting bigger valves, valve grinds and such, if need be, which would work out alot cheaper than buying heads and having them worked over. port and gasket match are already planned.

alright, nuff rambling. thoughts? ideas? yea's, nay's? think 325hp or so is highly possible? again, not building a ***** out race car. just a good, strong, reliable motor that'll scoot when i kick it.

thanks

 

for now, run it with the tbi heads. after a while decide then if you want to upgrade to beter heads. i did a s/d tpi conversion from tbi and enjoy it.

 

i have some questions too
how much power i get converting tpi to holley stealth ram? Can i get better MPG too?
if converting tbi to holley stealth ram will it be same power like tpi?

 

TPI doesn't make blistering hp, what is does well is make neck snapping torque. My TPI was the max you could get in a 3rd gen short of going the Firehawk Route which was already a modified Frankenstein Successor of TPI Called a T-RAM intake which made 45 hp minimum over the 350 TPIs 245, aided with LT1 pistons, forged crank, and such other mods the '92 Firehawk made like 350hp & 390 torque and is still today enough to beat a stock '02 LS1 Ram Air Trans Am WS6 @ the Drag Strip with the right guy shifting the ZF 6 speed.

 

What mpg you get in city and highway? And what you think about TPIS aka miniram intake?

 

Me ? I get 12 to 15 mpg in the city, and like 23 on the hwy on a good day when I don't Lead foot It everywhere, ( I have a Heavy Right Foot ) and tpis miniram will help you make more power of your not satisfied with stock. Usually you aid it by getting a Stroker kit and building a Nice 383ci, more cubes more power, or Longer strokes more power.

 

Get vortec heads. I know center bolt valve covers are ugly but those heads are cheap and with very little work and screw in studs will handle a decent lift cam and easily 500hp. I have seen guys get a set of vortecs for as little as 100 bucks.

 

wow vortec heads and cam only and doing 500hp?
can 383 doing without cylinder bore out?
what gain is with aluminum corvette tpi heads?

 

i've used vortecs in the past, in stock form, and worked over to various degrees. sure, they did alright, but the money put into them wasn't worth it to me. surprisingly where i live vortecs are gold. even a used set that needs total rework go for a weeks pay. i can find sets all day long for $100, but by the time i pay for gas, or worse yet, shipping, i'm into them more than what it's worth. not worried about centerbolt vc. just looking for input from those who have put the tbi heads on a mildly built motor with tpi. but i do appreciate any and all input for sure.

 

I didn't say it quite like that. With some work they are capable of that range of power. Some porting, slight valve job, screw in studs, and a decent cam. Not just a slapem and go job. But none the less can be done for pretty cheap.

383 cant doing without cylinder bore out.

Where do you live and how much do you get paid? Im sorry. I have grabbed brand new GM, never used sets off ebay for 500$. Used I see them go for 200-250 all day long. Summit repros are 600 for a brand new assembled pair.

Its the best bang for the buck head. We have made 400+ less money with vortecs than with anything else. Not to mention you can pick em up at the junk yard quite often for like 30 bucks.

I will bet you would be in it less money and making more power $ to HP with vortecs than with 305tbi heads, even with shipping, gas, hot tank, cleanup ect...