Picked up an 89 350 TPI roller motor last week with hopes of rebuilding it and dropping it in to replace my 305 TPI that's starting to go south.

I have never rebuilt an engine before. I have never taken apart an engine before. I have most of the tools needed (minus micrometers) and I'm pretty good with a wrench and have lots of patience.

Is this within reach? Should I start with a carb'd motor instead? The engine itself (block, heads, intake, guts) doesn't really intimidate me ... replacing the cut wiring harness, the ECM, the fact that my current engine is MAP and the 350 is MAF ... that's stuff that scares me.

Do you guys think, with the info I've given you, that I can pull this off? I'm fine if it takes me a year or two. I just don't want to spend a lot of time and money on it and then drop it in the car and it won't crank because I've effed something up.

Oh, I have lots of books and DVDs on rebuilding the SBC, SBC valvetrains, SBC heads, etc.

 

Like you, I am not up to speed on MAP, MAF & ECM but you sound like you are willing to learn which is half the battle. It would seem to me the key is making sure everything works together with your new motor, along with any smog requirements where you live. I would start doing some research on MAP to MAF conversions on this site under the 'search' feature at the top of the page. If you are going to be doing most all of your engine rebuilding yourself, micrometers and dial-indicator gauges are a must. You should be able to find what you would need while doing your research. Spending some time getting things together would also give you time to find a good deal on tools you need that you don`t have or line-up someone to borrow them from. You could also have a machine shop do your short-block and heads and you could assemble the rest which would eliminate some tools. Regardless of which way you go you will need to find a machine shop to do some of your work unless you get lucky and don`t need any machine work.

 

It doesn't matter whether it's going to have a carb or a TPI on top of it, rebuilding it is the same. Your current 305 top end could bolt on to the 350 to help minimize hassles.

 

I plan on swapping top ends and replacing the injectors. It's the ECM and wiring I'm worried about.

 

Ok, the wiring harness on the 91 and 92 cars is different than the 85-90 cars, as well as the type of relays used and some sensors(I have switched tpi systems around all the time, can you tell? haha) If I were you, to make this as simple as possible, keep your factory harness on the car, and swap your 305 tpi onto the 350. Get the 24 pound injectors, and your going to need a 92 model 350 knock sensor as well as the esc module for a 92 350 model. Take care to look at all the sensors that aren't mounted to the tpi set up, like the oil press, fan switch, temp sensor, because if they look different than the ones on the 350, take them off your 305 and put them on. Your also going to have to find a prom chip for a factory 92 350 car, because the one for the 305 will not work, unless you find someone to re-flash it for you.

As far as rebuilding internally, it's very straight forward. As long as you have the correct tools, and a good book, anyone with a little knowledge can do it. Just make sure you use plastigauge! Good luck, and if you need to know anything else, let me know.

 

What's to worry about? It's all in your car and wired already.

 

If whitedevil is correct that I can use my existing harness in the car with a few changes, then that would be nice. The wiring harness on my 350 that I'm rebuilding has been cut. Clean in two.

What do I need to know about the MAP/MAF difference?

 

You don't need to know anything about the MAF/MAP difference, because there won't be a difference, you'll still have the MAP from your 305. You're making this way too complicated. If you swap everything on your 305 over to the 350, there are no changes to worry about. You'll want new injectors, a new knock sensor, and a new PROM. That's about it.

 

http://tpiparts.net/installing_tpi_on_your_vehicle
Go to that or tpiparts.net then tech articles then you will see tpi on your vehicle. It is alittle easyier to understand how they put it. It don't matter what engine you use, what matters is what you have in your car. Apeiron is right on the money. He's saying use your cars electronics to control the new engine. The engine don't care how it's controled. It's easier to adapt the engine to the car than the car to the engine.

 

This clarifies a lot. Thanks, guys. I guess I am making this too complicated. You just have to understand that I've done hardly any engine work, and I'm trying to wrap my brain around all of this. I guess the best thing to do would be to wait until I get to the TPI swap part of the rebuild and then ask questions if I get stuck. I just wanted to make sure this was within my capabilities.