Mattkovitch

I have a 91 firebird with a 305 tbi. The oil pressure is very low, and I need to either rebuild it or swap it. But is it even worth it to rebuild a 305? I think not. I want a 350 and tpi, but I have a budget. I want to buy the motor and have shop do the swap. Can this be done motor included for under 2500?

eoj

Not sure about the TPI but I don't think you would be able to have a shop do it for that. I'm doing all the work except machining and I will be around 2500 for a carb motor

dmccain

iTrader: (2)

Easy swap to TBI 350 if you don't go getting a radical cam and such requiring a bunch of tuning.. Just some bigger injectors, esc module, knock sensor, and a chip tuned for the 350. Or, go carb and have much more power.. Getting it done for $2500..Wishful thinking.

someone972

iTrader: (2)

No way you'll find a shop that will replace the engine for that much motor included IMO. Maaaybe if you were just replacing it with another 305, but replacing it with a 350 TPI requires changing wiring, computer chip, etc.

Mattkovitch

what if i bought a 350 crate engine and used all belt driven accessories and starter from my 305 and switched to carb. is that something i could do myself? i was told i could use the stock fuel pump just as long as i get a fuel pressure regulator.

five7kid

iTrader: (14)

You could do the TPI swap yourself...

Our cars are in the "hobbyist" category. Having a shop work on them other than for things like alignments or custom exhaust is cost-prohibitive relative to their value. As previously mentioned, machine work on an engine rebuild has to be farmed out, but labor costs quickly escalate when you're talking about "non-book" work like an engine swap and induction change ($2500 for labor alone to do that swap wouldn't surprise me).

Now, having said all that, let's go back to the beginning. You said you have low oil pressure - is that because your dash oil pressure gauge reads low? These cars are notorious for oil pressure sending units going bad. If you aren't hearing lifter tap or rod knock, I'd suspect the sending unit first before something wrong with the engine internals. Verifying the oil pressure with a mechanical gauge is usually recommended. However, if you don't have a mechanical gauge laying around, it'll cost you as much to buy one as it would to buy a replacement sending unit. That should cost you about 1/100th as much as your engine replacement budget. If after that you have confirmed low oil pressure, you aren't out much.

If the engine is bad, I wouldn't recommend rebuilding the 305 (although that may be the least expensive way to get a fresh engine). If you're looking for an excuse to put in a 350, the easiest (and probably cheapest) way to do that is find a 350 TBI in the boneyard - they were in '88-'95 light trucks, and B-body passenger cars (Impala, Caprice, etc.). Just make sure it's a 350 and not a 305. Get the whole engine, TBI, ECM if possible.

Quick note: The f-body 305 TBI exhaust is horrible. Plan on upgrading it if you go to a 350.

Mattkovitch

Yeah I really don't want to take it to a shop for anything, labor costs are way too high. I'd love to 350 swap it but I don't think I have the money, for various reason my budget dropped about a grand and I'm working with about $1500 (unless I think this 305 will hold out long enough for me to save a little bit more), and I think it may be possible that the gauge is reading lower than it should, but I do get lifter tapping but not every time and not even all that often. Plus it runs pretty smooth, smoother than I'd think a car that while hot can't get 15 psi oil pressure even on high way speeds. I had someone from a Facebook group tell me they'd sell me a 305 long block for $50 bucks, but I'm hesitant bc I haven't heard it run (he says it ran good and has 60k miles on it, but I have no proof) and I'd have to drive 8 hours one way to get it or if Hes willing to ship it drop a couple hundred on freight shipping. I'm not super worried about performance and will settle for a 305 (it may sucks but its still a sbc) because this car is my only car and daily driver. Any idea what a junkyard would charge for a some what low milage 305 that runs good?