New to FSC - Engine Swap Question

[fishermanfloyd]

Hello all. First, a little brackground.

I currently own a 1997 Jeep Cherokee Sport 4wd. I rebuilt the 4.0 liter last year with fresh .040 bores, .010 .010 crank, new pistons, rv cam, valve springs, rebuilt head with new valve springs. I also upgraded the intake to a higher flow unit and installed a header. It has a high flow cat with 2.5" pipe to the flowmaster and tailpipe.

I came across a post on Craigslist with a guy who has a 1994 K1500 5.7l 350 TBI Ext. Cab Z71 who wanted to trade for a Cherokee. The truck has 121,000 miles. My Jeep has 147,000 miles, but with an engine with mileage of 10,000.00.

I already looked at and test drove the truck. It has been very well maintained with only a few minor imperfections with the body. The interior is near flawless. The 5.7l 350 TBI seemed like a dog, is this normal? Maybe it just needs freshened up.

My main question is this:

I currently have a 70s 2 bolt main block that is punched out .030 and is ready for a rebuild kit with a corresponding set of heads.

Is it possible to use the TBI with this block and set of heads? Is there anything that I will need to make it compatible? Any fittment issues to the 4l60e?

Any feedback that you can provide is appreciated as Im going to meet with the truck owner tomorrow at 3:30 pm to possibly seal the deal.

Thanks in advance.

[Badass69]

Search, it's been covered many times is my normal answer. Mind you the search on this site sucks at times so here is a quickie. Being a dog.... well it's a TBI 350 in an extended cab 4X4 with probably something stupid like 3.42 gears and 265 tires. Depending on what you are comparing it to it will be slow. That said every 93-95 TBI truck I ever drove seemed comparably doggy to the 87-92's. It might be in need of a tune-up, or like me it's just dog slow because in truth and reality compared to anything built in the the last 10 years or so, they are slow, stock anyway.

The older setup will work fine provided you elongate the center 4 holes on the intake manifold. The TBI heads has the center 4 at a 72 degree angle to the face versus 90 degrees for the other 8. If you cut the intake with a dremel out a bit it will drop right on the pre 87 perimeter bolt valve cover heads.

Personally why not just get a set of Vortecs and hop it up a wee bit. Some 70's smog heads are not going to even flow as well as the TBI swirl ports do in most cases and Vortecs are cheap. You need a new intake manifold but getting your hands on a carbed Vortec style intake is easy, then just get an adapter plate for the TBI and go from there. You of course will need a different tune, but even stock the truck would benefit from that. Not to mention depending on what you do even with your current old setup it will probably need a tune anyhow. Just throwing it out there.

[fishermanfloyd]

Thanks for the reply.

I tried searching, but couldnt find what I needed after browsing for hours. Most of what I found pertained to EFI to Carb questions.

I just wanted to make sure that I could use what I had in the shop with the TBI fuel delivery on the truck. Im going to meet the guy tomorrow to see if we can make a deal.

I guess I will search for Vortec heads as well as I happen to have a complete 96 R block in the shop with a spun rod bearing.

[Badass69]

Even better. With the L31 bottom end and roller valvetrain I mean. The stock Vortec truck cam is a decent torque grind and quite a few guys ( beyond this board) do the L31 swap in the TBI trucks. It's a good torquey engine. And yes to make it run properly it will need a PCM tune.

[fishermanfloyd]

Welp. I sealed the deal on the trade. The truck is 1994 1500 Ext. Cab Z71 4X4 5.7l. It is very nice. I will post pictures in a few days. Thanks for the help badass. I will let you know what I do with the engine rebuild.