Thread: S10 v8 swap

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I have a 93 S10 with a 4.3 TBI engine and 4L60E trans. I am planning a V8 swap and I want to retain the fuel injection (TBI) by using performance injectors for a 350, ECU, ...

My question is will a flat tappet engine work with the EFI system or will it have to be a roller motor?

Originally Posted by Bigbzc

I have a 93 S10 with a 4.3 TBI engine and 4L60E trans. I am planning a V8 swap and I want to retain the fuel injection (TBI) by using performance injectors for a 350, ECU, ...

My question is will a flat tappet engine work with the EFI system or will it have to be a roller motor?

Doesnt matter; they made TBI motors with or without. There's a place called Turbo City. They know all the ins and outs of GM TBI stuff. When I put a TBI in my son's 69 Chevy truck, they helped me a lot. Here's a link.

http://www.turbocity.com/

The S10 V8 swap is very much like the ones for Astro's.Primary engines to look for is 1989 to 1992 truck engines.Keeping as close to stock as you can will allow you to just extend some wires and plug and play.Of course to buy a donor truck is always the best way having all the parts you need in the donor.

Ok, another question. I have heads from a 305 HO that I want to use. If I found a 350 with roller cam, how well if at all would they do?

Do you know the casting number on the heads? The 416’s were decent for their intended application (305) and if you have these heads and they’re all cleaned up and ready to go – they’ll suffice. If they’re stock, they have 1.60” or 1.84” intakes and 1.5” exhaust valves. If they’ve been modified, there’s a high probability that someone installed 1.94” valves – making them very similar to the old “Camel Hump” heads but with shorter runners. The bigger intakes help on the fuel side but there’s only so much that can be done for overall flow and you’ll not come close to a set of stock Vortecs that are readily available and you won’t have to wonder if they’ll perform. These are also a thin wall casting and if machine work has been done you’ll want to magniflux the heads to make sure they’re not cracked. The head will ever-so-slightly cover the bore as they’re meant for a 3.736” bore opening versus the 4 inch 350.

If you do decide to use the 305 heads, check clearances very closely and know going in that they have small intake runners and 58cc chambers – higher velocity but less total volume. While the 58cc chamber will up your compression ratio, it can also cause problems with flat top pistons so I’d go with a dished piston. The 58cc chambers and the dished pistons should get you somewhere in the 9.4-9.6:1 compression ratio on a non-milled head (depending on gasket thickness) but you shouldn’t have to worry about valve-to-piston clearances.

Keep us in the loop and have fun
Glenn

thanks for the info guys. I cant remember what the casting number was but I know they have the 1.84" intake valves. They are in stock form and the only work to them has been a valve grind. They didn't need to be milled. I do plan on using flat pistons but thats only because I have a set lying around. The cam I have requires at least 9:5.1 compression and is a Summit Racing SUM-1106. I only plan to use these because they came with another project I bought off a guy and the engine he gave me was a 400 so they wouldn't work. I'm sure I'll be told to use something else lol. Let me know guys