1980 MC 229 to 350 TBI swap

[Yungjayuno]

Hi I am trying to restore a 1980 Monte Carlo with a 229 in it. I will worry about exterior later but for now I want to focus on the engine which is trying to start but wont keep turning over, May be battery or alt. Instead of putting work into this engine I have a friend willing to sell me his 94Chevy truck with 180K on it for 650 bucks. My initial plan was to find a 5.3 and go from there but one question I had was would the transmission/ engine mount right into my 1980 MC. I want to do away with all the computer things as I want to swap it to a carb'd setup. Would it be best to do this or go with a 4.8/ 5.3 ls engine carb'd

 

[Yungjayuno]

350 in the 94 chevy btw

 

[pencero]

If you are dead set on a carb'd setup it would be best to pass on all those engine choices and just get a regular early 350 truck motor from somewhere else. The TBI program is so hopelessly old and obsolete it is not difficult to set up a TBI system and burn a chip for it. I had a 93 fleetwood with a 350 TBI and was looking into the carb'd vs TBI thing and the benefits of the TBI such as highway mileage and daily driveability / reliability on a daily basis is much better w/ just some new cams and a chip you can improve economy and highway mileage by nearly 20% - and if its a swirl port you can have the heads ported to fix that too of course. Another good thing about the TBI is that you can always put the chip in your house when the car is out of season and then even if a thief peels your column 1 day he won't get away w/ the car unless he can get to the chip inside your house somehow. As for the LS it's not a straight swap and its very expensive. Putting a carb on a LS is ok but you can get way more power and high way mileage out of it with EFI and tuning it correctly w/ a chip too.. Unless someone is just basically giving you an LS for christmas it's a poor choice over just boring out a regular old 350 motor from the junkyard. Also, if theives hear you carb'd out an LS they will try to come steal your car because they can sell an LS for at least double what other motors are going for right now. An LS with a carb is a sitting duck to a theif unless its parked inside a house w security...

 

[pencero]

By the way that 94 truck has more to offer than just the motor. If it hads the 4l60e you cant even use a carb'd setup w/ that. I was going to try to put my caddy on carb'd setup and found out it wasn't going to work w/o some programming thats why the plan didn't go anywhere. You would pretty much be forced to use the trans in the truck with either of those motors and keep the computer stuff if its not an earlier '7oor4' with manual valve body as opposed to the 4l60e which will not turn on without a chip... If you put the 350 tbi connected to the little 3 speed trans it will most likely destroy it in less than a few years even if you drove like a grandma it won't shift very well; so you'd have to use the trans from the truck basically.

 

[pencero]

By the way I met someone who did actually stay with the crappy stock 3 speed auto / column setup b/c they are not really into driving much and they have a 350 tbi which they set to basically stock and it has nothing but a mild cam swap in it runs ok but it cant go over like 85mph w/out that 4th gear. Gets to top speed pretty fast though; but even with a 'trans go ' shift kit 90mph is about the best it will do. The small cams and small injectors make the TBI about the equivalent of 480 CFM stock but by running bigger injectors / cams and a spacer you can get it to more like 600cfm. It's important to know exactly how much cfm you are making though or you won't get the most out of programming your chip - and if you just guess and tell the programmer 1 thing the chip he sends you wont work very well then. You should be able to make nearly 20mpg w/ the TBI motor if you don't do much to it. Mine got 24mpg with the stock program until the head gasket started to go bad then sometimes it was getting more like 18-19 after that. Thats the other thing you have to look at too, the head gaskets go bad on these tbi motors thats why I never actually got my act together on the caddy too; couldn't afford to do the head gaskets and the intake manifold at same time so I let the project slide. Don't be me; if the intake manifold leaks and there is trace ammounts of coolant on the spark plugs on that truck you don't want to put that straight in it has to be rebuilt or it's totally going to waste your time and money for the next few years until you rebuild it correctly. If you use the 4 speed with OD you should be able to go nearly 140mph easily after doing all that stuff i just said. Too bad I used up my tbi 350 and threw a rod instead of sending it to be rebuilt in time. Those headgasket problems really do come out of left field so look at that sh*t up close and personal before you drop it in the car. Maybe check for leaks with a blacklight at night. Thats how I found where mine was coming from.

 

[pencero]

yo I'm sorry if I was boring but it just made me so mad when I drove the car and blew that engine this spring. I would definitely not ever put a 350 tbi in my car again without rebuilding it for the additional CFM and highway mileage programming gains this time. That headgasket issue totally ruined my whole spring and threw me into a huge fit of rage. If you go w the tbi either stay stock or rebuild all that sh*t properly and gaskets too. It would still come in half priced than building up an LS thats for sure. Otherwise like I was saying an older 350 truck engine w a nice carb ends up coming in way cheaper and can stomp on a stock 350Tbi. If you learn the ins and outs of the 350 TBI I have even seen one with a turbo before but it looked a little overcomplicated and complex for my taste. Putting a turbo on a LS looks much simpler. I would bet fat bucks and cash in easily that if you run the summit intake to convert to carb'd and don't redo all the gaskets including the thermostat that you will encounter all the same issues I had especially running a carb w/ more than the 480 CFM tbi was pulling through that old engine. W/o new gaskets that engine will take a sh*t w/ a 500-650 carb sitting on top of it you can bet that. Original factory gaskets was designed / warrantied only to 100,000 miles - it even said in the handbook to my 93 fleetwood

 

[Yungjayuno]

Thanks I will keep that I mind I may swap transmissions with someone to get a 700r4

 

[pencero]

good idea the 3 speed is fun around the 'hood' if you are broke but that noticeably absent 4th gear gets old fast! the 7oor4 just requires you to buy an iceman or gbodyparts.com crossmember. A few other companies make the crossmember too. If you decide going carb'd isnt that important to you, it is the same crossmember that can accomadate the 4L60E too basically. Hope this helps! PS, When I bought my 650 DP from holley it looked easy to set up the pull start to the back of the parking break release switch easily. You can just stand there looking at it and basically see it is designed w/ this in mind. The quadrajet carbs don't work without a computer unless you get 1 dated to the early 70's - and those have kind of mixed reviews for reliability on here. Best wishes to you w/e you decide. Glad I could pass on that 350 tbi knowledge; now it doesnt feel like such a waste having owned that motor and running it into the ground. Wish I would have known my 4L60E wouldn't take the summit carb intake w/o a programming or I would have went with the 7oor4 and pushed the engine for a few thousand more miles w/ a carb on top but I guess it wasnt meant to be. Ironically the trans that came out of the car was a perfectly good 7oor4 that just needed a good rebuild. You can find some of the last 7oor4's in early 93 fleetwood / 90-91 caprice / buick estate/ early 92-93 roadmaster or k5-k10 blazer, and some of the boxy f-body early 90s iroc / firebird & TA some of them had it too but not the ones w the v6 of course. Keep costs in mind - if you buy a bad 7oor4 it's at least $1500 for a decent rebuild and anyone asking less than that walk away b/c they dont know how to do it the right way then. The 350 trans I had rebuilt w/ a B&M kit for less than $800 out the door just a few years ago. If you get the T350 or TH350 w/ the B&M you can go like 100-110mph easily and I actually kept my column shift but I wouldn't recommend that it got boring kind of fast. Will probably get the shifter next time I build a 350 trans. But yeah its a whole different story about rebuilding a 7oor4 a shop I asked for a quote up the street from me said they won't even touch 1 unless a person is ready to agree $2100 and thats just to do the clutches/ innards and set it to stock thats not even like the 'performance gain' package which they want more like $2600 for that ; so basically you can always just 'grab' the 1st 350 trans you see b/c the rebuild so cheap but w/ the 700r4 dont just grab whichever is the 1st one you see find several and then pick the best 1 or it could set you back a couple grand!