Swap Carb to Fuel injected 350 Chevy.

beretta · Post by **beretta** » Mon May 23, 2011 1:23 am

Going to swap the old work truck over to fuel injected...

I picked up a intake and throttle body / wire harness / ECM from the junk yard on saturday.

Engine is a 350 that was rebuilt and has 2,000 KM on it so far. runs good but just so hard on gas. i think its standard bore but i know it has new pistons in it so it might be bored. i know it has a mild cam as well.

The truck i got the parts from was a 87 same old style but first year of fuel injected. I just realized the heads on it were the newer style as well. You can drill the 2 center holes on the intake to make it bolt to the older heads, but im wondering if i should just get the heads from that engine too..

Im debating on what heads would actually be better to use.. the newer style ones, or just drill this intake to bolt onto the heads on the engine now.. if i get a set of 305 heads it will increase the compression but would i have to run higher octane gas? would the newer style heads flow better or will i just be messing with compression ratio and stuff if i go with the newer heads..

If i do get the newer style heads.. should i take them off that same engine in the 87 truck or get some off a 90's truck ? would they not all be pretty much the same thing ?

And.. im not sure if it was a 305 or 350 in the 87.. if it was a 305.. will that throttle body and ECM still run a 350 fine since im sure the 350 would require a little more fuel.

The truck has 138,000 KM or 158,000 i cant remember and its only been 1 day lol....

I got a good deal though... i love that place.. i got a whole wack of stuff..
intake/wire harness/ecm for the 350.
1. lower and upper intake from a 3400
2. TA firebird tail lights, just cuz they were mint and ill either use them or sell them.
3. friend got a power steering pump for his car 97 grand am
4. found some aftermarket like new 6 inch speakers set of 4.
5. factory spoiler from some car with a cool 3rd brake light - was laying on the ground so i grabbed it.
6. fuse block for amp power wire
7. found a invisible fence control and a collar sitting in a car
8. im sure there is something else im missing LOL..

Got all of that for $40.00....... im going to try and go every Saturday this summer, spend less then 100 each time and just stock pile parts, list them online and go to swap meets and flee markets. if i spend less then 100 bucks each time it will be sort of like an investment and even if i dont get around to selling much in the summer, when im laid off in the winter i can sell parts and make some extra cash. the parts there are so cheap you cant just not go and get stuff lol.

woody90gtz · Post by **woody90gtz** » Mon May 23, 2011 8:00 am

The 193 swirl port heads on the 88-95 trucks are nothing special. They're decent for low end torque, but run out of breath at about 4000rpm. I think the older 350s back to the mid 80s had them as well. 96-98 trucks had the better 062 Vortec heads, but they require a special intake manifold to run a TBI on them and it's about $400. You can run a carb Vortec intake with a TBI adapter, but you're still talking over $200 at the very least.

Compression is great, but on a truck it can be a problem. I'm running 10.55:1 on 93 octane in the 355 in my Camaro, but that's because I have a good sized cam to bleed off some cylinder pressure. A big cam in a truck would mean sluggish response at low rpm, and when you put a heavy load on a truck it will have more of a tendency to ping. (Chevy built their 3/4 & 1-ton truck 350s at about 8.5:1 compression.)

I'm building my truck 350 here soon and I'm not going to bump the compression much if at all. It's a stock 9.25:1 and I might go 9.75ish with a thin head gasket, but that would be about it. I'm doing cam because that's one of the biggest downfalls of a stock 88-95 truck 350...but you said the 350 you're using already has one. What is the casting number on the heads you have?

Post by **Cliff8928** » Mon May 23, 2011 12:31 pm

Just FYI, if you do get heads from a 96-02 Vortec, they need to be from a 350 (L31). The 305 heads are not the same.

beretta · Post by **beretta** » Mon May 23, 2011 1:24 pm

Im not sure what the head castings are on the engine now, just stock ones.. its an older engine pre 80's its a 010 block. my boss bought the entire truck with the engine in it, it was rebuilt and drove less then 100 KM. not sure what cam is in it or what bore it is or nothing.. i just know it runs lol... when idling its very mild.. rmp moves maybe 50 to 75 rpms but the brakes are hard to push with less vacuum.

Its pulls pretty strong taking off, if i wanted to i could put it right sideways. i just put a 4 speed back in it which works alot better then the temperay 3 speed i put in it. we pull a 6 x 10 utility trailer with 2 ride on mowers and push mowers every day all week and it works real well.

Doesnt get very good fuel millage though, and i like to bring it home sometimes to do my own stuff and i hate putting gas in it lol, main reason i put my beretta on the road i was driving this truck as my personal vehicle for a couple of years.

I think im just going to make this intake fit on the heads currently on the engine and call it a day. see how it runs and i can later on change things up if i need to.

My dad has a set of camel hump heads with the small valves wish i could snag them but no chance of that haha.

I brought the truck home this weekend to do some things.. so far i have put $120 in gas in it and probably have to put more in to top it up by the time i go back to work tomorrow. i could drive my car all week on that. be real nice to see what the fuel millage is with it TBI.

woody90gtz · Post by **woody90gtz** » Mon May 23, 2011 2:10 pm

Well, the mileage on my TBI sucks...but it probably is still an upgrade from a carb. When I swap the Camaro from carb to EFI it will be multi-port though.

beretta · Post by **beretta** » Mon May 23, 2011 10:59 pm

Yes i remember my dads 91 chevy 4x4 TBI and when i got my licence like 10 years ago i used to put $60 bucks in that thing just to cruise around for a few hours at night. but that was 4 wheel drive too.

TBI has to be better then a carb. ive been debating on switching my 84 firebird to fuel injected when i build the engine for it, i know where there is a LS1 sitting i could buy although i would prefer just to buy the top end and put on my 4 bolt main block i have.

I just wasnt sure if the newer style 88 + heads would work any better then the older carb heads with a tbi intake, i guess ill just drill the center holes so it can bolt on and use the heads on the engine now. i dont want to get into taring it down more then i have to. probably do it in a couple weeks, i need to find a distributor all of them at the wreckers are gone, and need to get a electronic fuel pump. the tank on the truck i got the intake from was MIA.

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