hi,

in the process of acquiring a 85 s10 blazer 4x4 w a pretty clean body. engine is shot. im comtemplating on getting a used engine from junkyard, but at the same time considering an engine swap. do the later year 4.3
v-6's drop in? would i need the whole drivetrain + harness , computer and trans for this. can the v-8s be dropped in or mods are needed? would i need the engine harness and trans from the 8? much help would be appreciated. thanks!

 

Depending on the engine it has now its gonna require the same headaches to put a 4.3 in as a v8. Might as well put a v8 in it.


If it has a 2.8 and you don't feel like replacing the rad, computer, exhaust, and transmission but want more power do a 3.4 swap.

Swapping Your Chevrolet 2.8L for a 3.4L

Was running a hopped up 3.4 in my 87 and was happy with it. Just going bigger and need a v8 to power mine.

 

sounds kinda complicated. thanks for the input. if you swap a v8 you would need the entire drivetrain im assuming including harness computer, driveshaft?

 

i think that question you asked tells me you need to research more, the 2.8v6s were 4x4 i believe, as were the 4.3, no matter what engine swap you do it will need modifactions, the trans (if it were a 4.3) will need beefed up (corvett servo, shift kit etc) or if a 2.8 than more or likely a new one, and yes youll need a new computer and harness bc the v8 harness is different fron the v6, the driveshaft youll only need if the tranns is long/shorter than the orignal trans, but other than that you really just need to research alot, what you want/need out of the truck its, if you just replacing the engine to drive it, i would make it easy and through back the engine already in their with one for the JY

 

2.5s and 2.8s were options in 4x4s till 88, after that all 4x4s were 4.3s and something like 99% of all suvs were 4.3s. Very select few 2wds were 2.8s till 89 then all suvs were 4.3s.

Its not the servos that's the problems. The v6 trans were built with less clutch packs for the smaller engines. Servos might prolong them burning up but its only a bandaid.

I've never seen a s-series v8 harness. Always mod and use v6 harness. Keeping a carb a carb is simple. Keeping the throttlebody all you do is extend some sensor wires and use a chip out of a v8. His 85 has a cable speedo so he's gonna want to stick with a 86 or 87 ecm. His factory cluster is the only flat dash that has a place to bolt the vss in it that's required for fuel injection.

But his being a 85 its a carbed suv and either a factory 2.5 or 2.8. A rwd 2.8, 3.1, or 3.4 bolts to a 2.5 trans. Just gotta change the exhaust and rad, and wire it for fuel injection if that's what you want. Use s-series accessories and 4x4 oil pan to make it more simple.

If its a 2.8 and you want a simple bolt in bigger engine you can get a 3.1 or 3.4 out of a camaro/firebird. Just use the block and heads from the f-body and the rest of the stuff off the engine in the truck.

Not knowing what engine you have, the plans for it, or your mechanical skill level is handicapping any more help I can give. I've done a few v8 swaps so its easy for me to start describing stuff that might be over your head.

 

i can source a 3.4 and just swap over the accessories from the 2.8 and drop her in? do i need other parts? any wiring involved??

 

what year motors shall i look for??