I`ve had this 1988 k5 blazer for a little while now it had a new crate motor and it has 66,708 moiles but the guy before me destroyed the internals so now im giving it a 100% over haul and i have been wandering what to do about gas mileage and power ive heard lowering my gears down to 2.73 and keeping my 33x.12.5 but... didnt seem like that go so well while wheeling. so any suggestions to get 350hp+ and more gas mileage my budget is $2,500 maybe more if it sounds like it`ll make a good wheeler

 

I would NOT recommend 2.73 gears w/ 33" tires. It will be dog slow and won't really have an appreciable impact on efficiency. If you want to play with big wheels, you have to take a penalty somewhere.

As far as an overhaul goes, I would recommend you put as much money into the engine as you can factoring in a trans & transfer case rebuild if necessary. Maybe swap out the gears for something taller to get it back to near stock overall gearing (tires + gears).

 

i always kinda wondered if you ran 2.73s and bigger tires with a crapload of horse power how it would do. might be fun in the mud with a lot of wheel spin but wont get any compression when going down hills.

my first k5 i had had 2.73s and 38s. it was insanely slow. was doable in 4low but barely. lot of times i couldnt spin the tires in reverse when stuck. it would just grunt

 

I thought it was funny to hears 2.73s.. was wondering what would be better a holley 670cfm tbi are a speed demon im not to fimiliar with the speed demon if anyone has was wondering how much more power it gave?

 

Ok so now im at the plannign stage strippeed down the blazer its just the body and the engine is soon to be pulled out of they bay only problem is im stil confused if i should rebuild a motor and spend a few grand or just buy a motor with all the accesories?

 

If it were me, I would build the engine myself. That way I would know what is in it, not just take someone's word for it.

 

How much do you think that would cost?

 

You're idea for gears is terrible. There is no other way to put it. 4:10's is gonna be around what you want for gears. What i can see happening is with high gears like that you are always going to have your foot in the gas, because its going to be slow and gutless and you're just gonna be sucking back the gas. As far as how much its going to cost you to do a complete overhaul, the sky is the limit. I put probably about 8 thousand into my engine. But there is nothing stock about it anymore other than the block which is bored .30 over everything else is high quality performance parts. And i still need my NOS which is why i spent so much i built it right for a high hp kit one day. As far as hp and mileage go its hard to put those two words in the same sentence. I dunno theres a million different paths you can follow. I think you should talk to some engine builders in your area and really do your research, asking people on the internet while it might seem like a good plan will just get you confused because everyone has their own opinionated ideas

For 2500 dollars ive seen some decent built motors on CL around that price mark too just look around...once you get into it though be warned its quite easy to throw that budget out the window lol.

If you have an automatic transmission too do not neglect thinking about your torque convertor and also carefully consider your cam, these are 2 very overlooked pieces of the puzzle that make big differences. I would suggest a cam with a duration over .050 and something like a b&m holeshot 3000 torque convertor if you want some serious bottom end which is what usually is desired by wheelers. Im sitting on this mistake right now myself i didnt know as much as perhaps i would have liked to when i did my build, so next spring out comes the cam and torque convertor for replacement with what i just mentioned :P Im sitting on like 450ish horse with no bottom end it blows lol. Plus im on 36's with 4:10's which is also seems kinda weak too =/

 

I`m not saying im putting 2.73s in i thought it was funny to hear im gonna be putting in 3.73s and being in NC not to many people have the greatest ideas..
but i have a 700r4 tranny and what would youy say would be the best for a enginen pushing 380 hp. through my research.. these trannys give out when towing so what would be the best overall transmision?

 

TH400 is by far the strongest and most dependable tranny gm ever made as far as i understand it. It is only a 3 spd though, no OD. For towing thats what you're going to want for a tranny out of the automatics anyway. Thats what i have in my rig works good. I still dont know though if you're going to be happy with 3.73's either though, speaking from experience im running 4.10's with 36 inch rubber and im really saddened at the low end performance atm. Im easily pushing 400 horse. It may not be all gearing issues in my case though, as i mentioned before i made poor choice of cam i think, and i knew nothing about torque convertors and just threw some random one in there that was on my friends truck. When i started with my mostly stock Blazer i knew nothing, ive definitely come a long way and learned alot and its been lots of fun