i could have sworn that i read somewhere the LA and Magnum blocks had different mounts, but that each was interchangeable within its own set (all LA blocks have same mounts, all magnum blocks have same mounts). in fact i think i read that in the FAQ

 

They use different mounts but they both have both style mounts. The LA's use the EAR style in the front of the motors which Magnums have in the same location.

The Magnums use the 3 mounting bosses in the middle of the engine. The LA's have the bosses but some have them drilled and threaded, some don't.

 

Anything more than a V8 throttle body is throwing money down a rathole.
Do watch the LA cams- fuel pump lobe, length of the input, may be other differences
But a cam is not worth the money (you do not have much low end to trade off)
Either
360 swap (engine and trans with wiring harness and computer)
Or
(heresy follows)
a late model Chevy and trans
both much more cost effective.
late V8 Chev may weigh about what your V6 does

 

My Uncle wimped out on the turbo build. He thinks it will take to long to get going.

So I am looking for more options. He still doesn't want to do a V8 conversion even though I have a 5.2 I would give him for the truck.

I guess my only other option is converting the LA block to magnum heads. The build is going to be a high compression Magnum conversion. The stuff I can think of that I need from the Junk Yard is:

magnum heads
intake
TB
timing chain cover
accessory brackets
pulleys
camshaft
engine wiring harness
fuel rails
Manual trans PCM
Magnum tappets

Are the V6 magnum heads prone to cracking like the V8 magnum heads?
Is there anything else I'm missing on my to-get-list?
I know the magnum V8 cranks are a little lighter than the LA cranks, does that apply with the V6 cranks as well?

 

Just get the Magnum motor block too, not just the heads. The LA's engine will need oil passage drilling and other modifications to make the Magnum heads work. Also the bolts on heads that hold down the intake are at different angles, so the intakes are not swappable.
Installing a complete Magnum motor with wiring and PCM and all is going to be best.

All in all your best bang for your buck since your swapping everything around is to do a 5.2 or better yet a 5.9 Magnum swap.

 

It shouldn't, there is a hole in the deck of the LA block for oil to go up to the valvetrain, that just needs to be drilled and plugged. The oil goes up through the pushrods on the Magnum.


I know but he doesn't want to do it.

 

If your uncle isn't going to do the v8 swap or the turbo upgrade then I would suggest saving your oney and buy you a Dakota with a bad motor and use the 5.2 you already have and do the swap yourself. Its not that hard to do the swap.

 

I get decent gas mileage with the V6, and was going to try and squeeze out a little more with this build. I got 21-22mpg driving from AZ to PA. Will I lose that mileage with a 5.2 swap with MPI.

 

No matter what I did to my 89 v6, I just couldn't get anywhere near the power I desired. I tried new exhaust from manifolds back, new plugs/wires/distributor, cold air intake, anything that I could do without pulling the motor. Anything more than that cost too much money for it to be worth it in my opinion. Sadly, the LA 3.9 is just not a performance engine. I have no regrets from my 5.2 magnum swap.

 

Alright I kind of talked him into the V8 swap, if we can get the wiring harness and transmission from the junk yard.

If we can't we are just going to rebuild the V6.