I got a 84 k10 with a 350 with 35's. I want to stick 44's underneath it but I want better mileage then 3mpg from a gasser. Would I be best to go with 6.2 with a turbo, a 6.5 with a turbo, or a 4bt swap. The 6.2 and 6.5 should just bolt up where the 350 is right?

I got a 84 k10 with a 350 with 35's. I want to stick 44's underneath it but I want better mileage then 3mpg from a gasser. Would I be best to go with 6.2 with a turbo, a 6.5 with a turbo, or a 4bt swap. The 6.2 and 6.5 should just bolt up where the 350 is right?

Pretty much......

This would be better off in the Frankenstein section though.......

If your set on turbo then a 6.5 would be a better setup. able to get more boost due to lower compression and coated pistons (i think). 6.5's are quite a bit more expensive and unless you get a pre 94 (again I think) you need electronic garbage. 6.2s are cheaper but you also have to get a turbo.
Also even though the motors mount up there are other things to consider such as return line system, hydroboost for the brakes, glowplug system that may not come with the engine diesel torque converter and governor if it's auto, and other stuff I can't think of.
Still going from a carburated 350 to a 6.? diesel you'll save hundreds if not thousands a year in fuel. I used to spen abou $3500 a year now it's closer to $1800. Also I don't have to worry about seatbelt tickets cause I have nothing else to do waiting for the glowplugs lol.

sorry guys i was feeding wrong info on other threads. the pistons in a 6.5 are anodized (im pretty sure on this) so they allow higher safe EGT's. the higher boost is just from the lower compression and better head gaskets.

6.5's are quite a bit more expensive and unless you get a pre 94 (again I think) you need electronic garbage.

You don't need the "electronic garbage" unless you choose to go electronic. All you really need is a mechanical injection pump.

i love the term you gave the elctronics. garbage! i dislike them as much as you. but i guess they work.

The tops of factory 6.2 pistons are also anodized. The 6.5 piston crown is quite a bit thicker and helps to resist cracking. Compression ratios of stock engines are close to the same between 6.2 and 6.5 unless you build an engine with low compression pistons. My recomendation is go 6.5 because you can't beat cubic inches.

The tops of factory 6.2 pistons are also anodized. The 6.5 piston crown is quite a bit thicker and helps to resist cracking. Compression ratios of stock engines are close to the same between 6.2 and 6.5 unless you build an engine with low compression pistons. My recomendation is go 6.5 because you can't beat cubic inches.

Would you use the turboed 6.5 or the one without and put the turbo on?

There much of a difference between the pre 94 other then electronics for the 6.5?

I think in '97 they got oil squirters, which ended up being a headache as they cause cracking issues. You'd have better luck asking 6.5 specific questions in the 6.5 forum though. Also, I believe this question is answered in the 6.5 FAQ at the top of the 6.5 forum.