[dpl096]

My wife's 1990 YJ 4.2 is taking a puke. It has the Howell throttle body conversion on it and this is a real shame as it's a solid running Jeep. Just so happens I have a dependable 1997 Vortec V6 out of her Blazer that she rolled 5 years ago. It's sitting on an engine stand in my basement. I'm not thrilled with the idea of a salvage yard swap out ... so here I'm sitting starting to ponder this switch out project and to be honest I'm more than full of questions.

I've been reading about the 716131-A Advance Adapter and engine mount kits. I know a header will have to come into play as will mating up the exhaust. This really seems like a daunting project but it's my cheapest route it appears....

I welcome any and all recommendations and ideas ... Thanx!

 

[89yellowjeep]

Given you have the investment in the Howell TB conversion why not just build the 4.2 or get a salvage 4.0. SBC swaps seem to seem to involve multiple steps such as as drive train adapters, gauge hook ups, etc. just a thought. Good luck.

 

[Luckymac]

A remanufactured 4.2 will be cheaper than a conversion.

A salvage yard engine, while certainly cheaper, will be a crapshoot.

Less daunting than a engine swap to Chevy and less expensive than a re-man motor and more certain than a salvage motor is for you to pull the dead engine, disassemble it completely and take the bare block to a machine shop for boiling, cylinder and crankshaft bore and replacing of the camshaft bearings.

If you have the wherewithal to do an engine swap, you should have the ability to rebuild an engine.

Put a pencil to the cost of each and then it will be easier to make a decision.

For me, I would go with a remanufactured long block, but God has blessed me with a good retirement. If a guy has a family to support rebuilding his existing motor may be the best route.

Good Luck, L.M.

 

[brent in az]

I thought about this for a couple days but I didn't have any ideas. I am all about the CHEAPEST route if quality is not sacrificed.

I just couldn't tell if the engine was dying or the carb was dying or both? No matter.

The vortec is cool. All you need is the $500 adapter. I assume you have the harness. New motor mounts. You get to keep your tranny and tc. Unsure about front and rear driveshaft lengths or relocation. Plus about 10 other compatibility issue upon swapping.

So you could do this for a cool $500 bucks, or $1000 bucks worst case scenario. You also never mentioned if wife's Vortec suffered any damage in the rollover.

Could be a $1000 project. Do the math the best you can. If you reckon this could be $1000 then...

...with that money could you consider some kind of efi/tfi for the 4.2? A rebuild, and resurfacing of head? Pistons, rods, valves? Don't hear many stories about the 4.2 being on death's door...

I guess what I'm trying to say is, if faced with a $1000 project...I'd choose to restore the jeep instead of a chevy swap.

If you did your math and research and the vortec swap is just that $500 adapter, simple as that, then go for it.

 

[Nubby55]

I don\t think you can do the swap for $1,000. but maybe you can, but the 4.2 will still have more TQ. If you mill the head down and install an RV type cam, it will have a lot more power than it did OEM. You can also get a 4.0 block, then reuse your 4.2 rods and crank and build a 4.6 or 4.7 Stroker motor and have way more power and TQ than ether the old rngine or the Chevy V6.

 

[89yellowjeep]

I don\t think you can do the swap for $1,000. but maybe you can, but the 4.2 will still have more TQ. If you mill the head down and install an RV type cam, it will have a lot more power than it did OEM. You can also get a 4.0 block, then reuse your 4.2 rods and crank and build a 4.6 or 4.7 Stroker motor and have way more power and TQ than ether the old rngine or the Chevy V6.

Nubby 55, what is an RV type cam? Not familiar with that term. Thanks

 

[kruger]

Here is a link to the thread where I did a Vortec conversion. Granted, I came from a 4 cyl AX5. But, you can get the gist of what is involved with this swap. I had lost more to think about than you are looking at, but you may get a few nuggets if info out of the thread.
http://www.wranglerforum.com/f118/89-yj-with-4-3-vortec-191172.html