91 Sonoma 4X4

[shvlhead.45]

I have one, 4.3L engine, a/c, auto...  Live in the Texas hill country and I'm tired of this little truck struggling going up hill and down shifting all the time.  Hill country gas mileage sucks too.

Has anyone ever put a small block in a 4X4 Sonoma/S10?  If so, what is the PITA factor.

Looks like wiring harness, computer, fuel system and TBI are pretty much plug and play.  Hard part is shoe horning it into engine compartment and using a pusher type electric fan in front of the radiator.

Anyone done this swap.  I know about JTR's book and if I decide to move past consideration the next step is getting the book.

If doable with out too much PITA factor, it'll have good power going down the road.

v/r
SH.45

[Lloyd Smale]

lots of s10 swaps have been done. I think summit even handles a conversion kit to do it.

[shvlhead.45]

Plenty of 2WD swap kits and accessories but the 4X4 not so popular.  Will do more research as I get closer to doing the swap.  May just find a 88-95 PU as 4x4 is not essential.

TM,
SH.45

[R.W.Dale]

I've done a 2wd v8 s series and it was a snap.

A 4x4 would be a royal PITA as as there's not anything easy to fix on one stock much less with a v8

I'm a little perplexed a 4.3 S-15 is one of the more powerful lil trucks and should fly up and down hills without breaking a sweat leading me to believe something is wrong with yours. Either way a 4.3 is just a 350 minus 2 cylinders so just about all the same hop up approaches apply. if it were me I'd spunk up a 4.3 and skip the v8

some quick things to REALLY wake up a TBI GM engine
bump the baseline timing up 2 or 3 degrees
make your fuel pressure regulator adjustable and set the pressure at 13psi
open up the exhaust

[shvlhead.45]

You are right about not much room for working on it now.  I have a 95 C1500 standard cab, short/step p/u that has a lot few miles then the Sonoma and it struggles on the hills, 99 Suburban rolls right over them.

Well, the odometer quit at 351,334 back in 07 (it did sit a year while I was deployed (OCT 07-OCT 08), has by my questamite in the neighborhood of 375K now.  I got it to use just as a hunting rig but it's turned into more of a daily driver. 

Engine has ballpark 100K plus on a remanufactured long block, trans has 150K plus on a remanufactured 700R4.  It has the big bore Holley throttle body, K&N a/f, new plugs, good brass terminal cap and rotor.  I know I need to put a set of wires on it and a fuel filter but but didn't think either were bad enough for immediate replacement. 

Cold weather broke here, will throw a timing light on this thing and bump the timing up 3 degrees and will go ahead and get the plug wires and fuel filter and get a fuel pressure regulator and bump pressure a little.  Note: Fuel tank and pump were replaced not long before I got the truck from my brother who is original owner.

v/r
SH.45

[Hooker]

Here ya go
http://www.s10-4x4.org/

Pat

[Lloyd Smale]

got to agree with crocus. We had a fleat of 4.3 s10s at work for the meter readers and they were stout little trucks. I sure couldnt see one stuggling on any hill. Longevity was excellent with them too. Transmittions were the week link but thats the way it is with any gm auto trany.

I've done a 2wd v8 s series and it was a snap.

A 4x4 would be a royal PITA as as there's not anything easy to fix on one stock much less with a v8

I'm a little perplexed a 4.3 S-15 is one of the more powerful lil trucks and should fly up and down hills without breaking a sweat leading me to believe something is wrong with yours. Either way a 4.3 is just a 350 minus 2 cylinders so just about all the same hop up approaches apply. if it were me I'd spunk up a 4.3 and skip the v8

some quick things to REALLY wake up a TBI GM engine
bump the baseline timing up 2 or 3 degrees
make your fuel pressure regulator adjustable and set the pressure at 13psi
open up the exhaust

[shvlhead.45]

Hooker,

Very informative site, thanks much, have learned a lot from just scanning.  While use the site, links, and the JTR book(s) if/when I get going on a V8 swap.

Krochus and Lloyd,

My 95 C1500, with some tuning, I was able to get it pulling a consistant 19-20 mpg for mixed local driving and while better than the Sonoma, it to won't pull a hill of any size at speed w/o dropping out of OD. 
The Sonoma will only pull down about 13-14 around town, 16 to maybe 18 local mixed driving and a best of 18 running the hill country.  When I first bought the truck, interstate hwy mileage was 22-25.  Don't know what the weight difference is betweent the two trucks and will check and that may be a factor.  These two trucks and a Safari van are the only ones with the 4.3 that I've had any real exposure to.  Grew up with L6s and they didn't seem to be bothered much by much other than the steeper hills.  I'm going to check the timing, change fuel filter and replace the plug wires and see if that makes a major difference.

Thanks Much,
SH.45

[30-30man]

The cheapest thing to do is a gear swap.  You'll have to do both front and rear axle but should be able to get it done at a shop for $1500 or so.  Don't even think of going to the dealer for this as it will be over $3000.  A smaller gear will cut your gas mileage back a bit, but will make a world of difference.  A 4:56 or shorter in both front and rear is what you need.  I have a 2wd version I did a marine 4.3 swap with.  It has turned out to be a good truck.  I had the rear end changed to around 4:11 and I wish I had gone to 4:56.  It has all the muscle I want it to have.  I've hauled some heavy equipment with it.  It tows my Massey Furgeseon 240 with ease on flat roads.  Now I haven't hit many hills with it as I am in pretty flat territory.  Trailer and all it is about 6-7000lbs.  It's the only truck I will let my workers drive as I know they can't do much more to it than has already been done.  It has no a/c or radio to cut down on joy rides.  It does have heat though.  We hose it out about once a month.  Right now as I type it's loaded with two 200gal propane tanks for the incenerator.  Good luck

[Lloyd Smale]

check your catalitic convertor for pluggage first then have the timing checked. Could have jumped time. Those and possible trany slipping is about the only thing that would effect gas milage and power that much.

[shvlhead.45]

30-30man, gear ratios you mention a pretty low for as much as I have that truck on the road. 

Lloyd, I'll recheck the cat and check the timing/set it up to about 3* advanced.

All that provided feed back, thanks much.  I'll do this work then report back with results.  I think that one day it will probably get a Vortec 350 with TBI intake just for fun.

v/r
SH.45

[rwng]

I also find it strange that a 4.3l S truck is under powered. I had 2, S trucks but both with the 2.8l V-6. They weren't that strong but a friends truck with the 4.3 seemed like a monster to me. Along with other suggestions, did you ever try adjusting the TV cable for the tranny? If it's out of adjustment, it will make it sluggish and shift early and drop in and out of OD too.