91 trooper engine swap

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91 trooper engine swap

Postby Nodnarbbrandon » Mon May 10, 2021 12:06 pm

I have recently gort my 91 trooper has the 2.8lwith auto tranny it is getting up there in miles at almost 270000 miles. So i am thinking probably goodtime to start looking into a new motor. Was wondering if anyone knew what motors were compatible for the easiest swap i have heard S10 2.8 and 4.3 are. And how hard is it to put a manual tranny in if i were top get a new motor. Thank you for any info or the push in the right direction
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Re: 91 trooper engine swap

Postby Shawn Anthony » Mon May 10, 2021 10:25 pm

If you are needing to replace the engine and transmission might as well drop in a 350 V8 and a eaton 5 speed or a 700r4 if you prefer an automatic.
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Re: 91 trooper engine swap

Postby giusedtobe » Tue May 11, 2021 9:15 am

There is a whole thread on motor swaps for the 1st gen troopers. Depends if you want to use existing motor mounts/trans etc.

If you are good at fabbing motor mounts and other stuff then the sky is the limit like Shawn said. I can't imagine how tight a 350 would be in that thing though. I used to have a Merc Mountaineer with a 5.0 and that thing was majorly shoehorned into the engine compartment.
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Re: 91 trooper engine swap

Postby DSUZU » Tue May 11, 2021 4:38 pm

"S-10 2.8" is slightly different (starter on wrong side and oil filter housing different). You COULD get a special jig and drill starter holes on the correct side and use your existing oil housing.
4.3 - completely different animal - ain't going to happen w/o extreme modifications.
Auto to manual conversion: don't attempt without a complete donor vehicle available. All front exhaust is different (4-5 pieces) front and rear driveshafts are different. Crossmember will have to be moved. Also need pedal assy, tranny, clutch, plumbing.
Installing ANY other engine will require extreme electrical modifications. Dennis
1991 LS Trooper 2.8 V6 5 speed conversion (Sold)
1989 LS Spacecab 2.6 5 speed 4x4 manual hubs, Rodeo torsion bars, extended shackles, 2" lift, K&N air filter (drop in), dump bed conversion, burgundy interior change, warn brush bar. Engine is bored .020 oversize and upgraded to 1994 pistons, head and EFI system.
Previously owned: 1987 Trooper II LS, 1989 Trooper (parts only), 1994 Trooper 3.2 Auto, 1997 Rodeo 2.6 5 speed, 1993 shortbed pickup 2.3 (project - sold) 1992 Rodeo 4x4 LS (parts car, devoured by Spacecab needs) plus some 70 plus other non Isuzu vehicles over the years. 1994 Amigo devoured to provide head and EFI system.
Heavily damaged by engine compartment fire while driving on March 24th 2018, condemned by insurance company and taken on March 30th 2018 :cry:.

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Re: 91 trooper engine swap

Postby Ed Mc. » Tue May 11, 2021 11:09 pm

A 3.4 out of a '93-'95 Camaro/Firebird would be a pretty straightforward swap. You do have to drill the block for starter relocation to the driver's side, but there's a drilling jig kit for that: http://rodneydickman.com/product_info.p ... cts_id=179

The swap uses all of the 2.8's accessories, intake & exhaust manifolds, timing cover, distributor, flywheel. They all bolt up to the 3.4, which externally is almost indistinguishable from the 2.8. It has a crankshaft with larger stroke, and larger bores, significantly more torque than a 2.8 and way more HP potential, depending on how you build it. Up to around 180-190hp with performance cam and other hot-rod techniques.

You've a good idea there, to change to a manual transmission; the 4L30E is trouble-prone and putting a hi-miles trans behind 160+hp is a recipe for failure.

Best thing would be to find a wrecked or rusted V6 Trooper or 3.1 V6 4WD Rodeo and rob the transmission, mounts, pedals, hydraulics, etc for your swap. The MUA5 is a plenty-strong trans and the 3.4 won't stress its limits. I can't recall if the rear driveshaft is different between manual and auto, but if you have a donor rig sitting there, you'll have every part, nut, and bolt you need to complete the transmission swap.

If you'd like some info on this swap, send me a private message with your email address listed, and I'll forward the swap info files to you.

I have a 3.4-swapped 1990 Trooper LS and have been very happy with its performance over the last 19 years. They'll probably bury me in it!! :mrgreen:

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