I have a 2001 2dr Blazer 4.3 5spd. I just put a used motor in cause the original spun a rod bearing. Now I need a little advice. I'm thinking of either rebuilding the original 4.3, porting and polishing the intake, heads, and getting the block bored, with a mild Cam, rollers, higher psi spider, and a custom tune etc, or getting a low mile Ls1.

 

If you have the money go LS1

 

The V8 conversion will take longer than you would think. It will cost you more than what you would guess. You will have more fun than your wildest imagination could dream.

 

With my knowledge and experience Im pretty confident that I can do a swap in under a week. But I'm not sure on them reliability on a built 4.3 cause I suffer from lfs

 

Yeah confidence is a good thing. If you have fab skills that you are proud of, it will take you longer than you think. Much longer. I dont mean to be negative, cause its going to be a journey. You will test your skills and the fun part is you will improve them.

I'll subscribe and check back in a week to see how far you've come. If I can be of assistance just holla. Hint (where the ecm harness passes thru the pass floorboard is critical as is the proper amount of engine set back, there is a low pressure accumulator in the tank that wont take the V8 pressures.

And they think mechanical bull riding is fun!

 

Im a fabricator by trade, but I found an ls1 swap kit wit shorty*headers, adjustable motor mounts, and a wiring harness adaptor for the $300. Also I have the Nv3500 tranny that will bolt right up. But I'm leaning towards building the 4.3

 

I too am a fab guy with cnc lathe & mill skills as well as panel beating. I can lay a stack of dimes overhead. It still took me 3mo. When I did the convert there were no commercial headers so I made my own .090 stainless (the collectors took 6/7 days, back gas didnt work well so I bought a small sand blast cabinet and gassed it). The motor mounts were 4130 cond n .250 and as I remember the right one was solid the left one and trans were urethane. Adapted the donor harness which had to be extended about 4in, ( a day at pick and save to source correct color code patches). I could go on, but if you are in fact a fabber and not an engine builder go V8. Its gonna be a wild ride,( referring to the journey) not necessarily the truck. The truck will speak for itself and the skill of its builder.

 

I've decided to build the 4.3 since there are numerous ls swapped vehicles in my area. I'm getting the block acid dipped, painted and bored .030 over for $150

 

What is lfs?

 

Lead foot syndrome? If I have to pull a 4.3, a 4.3 will not be being going back.