i have a 85 trans am w. 305 tpi. im going to install a new 350 crate when that 305 is done. can a swap the tpi system with the intake onto the new 4 bolt main 350?

 

Yes you can but youre going to need an AFPR (adjustable fuel pressure regulator) for the increase in fuel demands. Or you can upgrade your injectors. Also youll need a 350 PROM since they are different as well.

 

obviously the afpr would be cheaper but what psi injectors would i need anyways for the 350? i am familiar with prom but what exactly does it do, is it like a sending unit? and what about air delivery, go with a bigger throttle body like 58mm or bigger?

 

you need the 350 knock sensor aswell ,they have different part numbers

 

the only differences between the 305 TPI and the 350 TPI is the injectors and the PROM. Some have said the knock is different, but although I have seen several different part numbers, all I have used have acted no different.
- this is from personal experience, as well as other posts on this board.
NO, you don't need a different TB. Until you hit a MUCH higher power level, it will make no difference. - Also, the only real difference in the factory 305 vs the factory 350 PROM/chip is the injector constant, which is programmed for either the 305 19lb injectors or the 350 22's.
I've got a 305 MAF TPI set-up sitting on a Vortec headed 350 in a buddy's 95 Tahoe. Stock chip/injectors/everything. Ported heads, plenum, 1.6 roller rockers, headers, dual exhaust. - Truck runs great, no lean condition or anything else, gets about 17 mpg town, 20 highway(@ 80+). This is not to say this is the right way to do it, but it'll work fine. This truck was built mostly for grunt power and fuel mileage, so a hipo situtaion could be different, but if you're going for performance, you should have it tuned properly anyway(even stockers can find more power on the right tune)I will be switching it to a 87 350 chip and 22 injectors in a month or three and I'll see if there's any difference.....

 

so the fuel pressure should be exactly the same for a 305 and a 350 right?

 

yup . Although my stocker ( 305 ) was hovering around 46 psi

 

I have done the swap in a 1985 Iroc..
305 TPI to 350 TPI all I did was add an adjustable regulator. The car ran great.. still does same everything else.. well I added a stall for the mild cam.

 

If the TPI is coming from an 85, chances are it is the older style heads with the perimeter bolt valve cover. If you are going to be putting this on a newer 350 with the centerbolt valve covers, the intake will not bolt up. You will have to modify the center holes on the intake as they are at a different angle on the newer heads.

 

You will also need an automatic spark timing module for an 85 5.7, got mine for about 70 bucks from NAPA

 

D's89IROCZ<SCRIPT type=text/javascript> vbmenu_register("postmenu_2846437", true); </SCRIPT> that sounds nice dude!!!!! well thats plenty of info to keep busy thanks as far as the intake not bolting up being that the thread is at a different angle en all, what im actually gonna be doing is mounting that tpi on a new crate 350, i was sugested to use the goodwrench 350 /290hp one, still not sure which motor that is but would the angles be different on that u think? im gona try to find out what heads they are for now.

 

this sounds like something the TPI intake would mount to!!! 350 crate The cast iron cylinder heads have 1.94" intake and 1.50" exhaust valves wit 76 cc combustion chamber. These heads have the conventional 90 degree with 12 bolt intake manifold attaching design used from 1955 thru late 1980 12 bolt postion @ 90° to the intake/headflange.

 

Fuel pressure is different for a 305 and a 350. For a 305 fuel pressure should be 42-46psi where a 350 should be 35-39psi stock.

 

thanx man ! It's a single 3"dynomax ultra I pipe , C-5 corvette cat , IMCO 3"in/out ( single out pipe) with SLP 1.75 headers

 

I would go with the crate motor, mine only cost me 1500, heck of a deal from GM I just got the exhaust back on mine, and it runs excellent, now for the body work.