i just got a 1985 z28.i swapped in a 350,it had a 305 with a carb.but it used to be fuel injection.i don't know if it was tpi or tbi,and the harness is pretty hacked.i would like to go with the tbi route, so i can use the air gap manifold i just bought,if tbi is good for supporting 400 hp.if so what cfm throttle body should i get,and i may be wrong but you can't use a noisy gear drive for FI.thanks for the info.

 

almost any fuel injection can support that horse power its just tbi engines came w/ so many bottle necks that they r unpopular choice for building hp...take away those bottle necks then do what all egines want air in air out. the main restrictions on these engines would be the heads and cam if im not mistaken the swirl ports can be made to flow but for a couple of bucks u can pick up much better platforms to start w/ for that much hp though u may wanna go vortec or after market for the better flow they offer straight up before porting. as for the cam not much u can do for that other than change it out to a cam w/ alot higher lift but keep in mind u gotta be careful your pistons clearance when goin w/ monster lift and u also have to machine alot of heads to accept such springs. but my main concern is u wanting to base your desicion for what type of fuel injection u want to use cause of a intake manifold. go w/ what u want but just remember there is no replacement for displacement so if u have a 350 y not build that and slap your choice of fuel injection on it. im not sayin a 305 wont make hp (thats what im bout to start my mods on) im just sayin for the same stuff and probably same or less money u can do it all to the 350 u got and get better results....but i am still very fresh at this so these r just opinions u have to make up your mind what route u wanna take.

 

ok,i was looking under the passenger side dash,and there is an ecu.i ran the vin number and the engine code is for a 305 4bbl lg4.so is it FI or carb?

 

that would be carb.

 

TBI will support up to 500HP which is proven in math. Havn't seen any examples yet.

 

86 has a CC q-jet. Not half bad. With some freshening up and a few mods thatll support some power as well.

 

most of the carb cars in the us still had some computer controls...if u r that worried tbi will choke your hp u could always go crazy and spring for one of those four barrel tbi systems or you could fab up somethin even crazier and go w/ three stock tbi on a six pack manifold of some kind, but i dont know if either have been done on this board just an idea

 

I'll be installing a 450hp TBI setup this winter in my car. I got a TB that flows 750cfm, using an adapter plate to bolt it onto a victor series manifold.

 

How did you solve the fuel problem?

 

My dart iorn eagle 230cc headed 383 with a mild cam will be 450 HP. I am going with a Performer RPM carbed intake, holley projection adapter, and a 454 TBI.

I have the fuel side under control. My fuel will be fed by 454 injectors under high pressure. I have on my current engine a VAFPR with a late model 454 regulator spring in it. The current pressures are 32 PSI @ WOT and no vacuum but drops to 22 psi at idle with 20 in/hg vacuum. My current setup is using 4.3 injectors to feed 245 RWHP, still has a super clean smooth idle, and passes the dyno smog with flying colors. Just don't look at the VE tables.