Commando Engine Swap

[C4ptnCh4os]

Ok so this is my first major project & im only 19... my dad wants to go 50/50 with me on a Commando... don't have it yet so no pics... I have a basic plan for the build which includes a motor swap. My question is how hard is it to drop in a big block? I know a SBC is more or less stright forward... but I really want to build up a Buick 455. (A runner will cost me 500 local). Hacking & rerouting major shit is out of our skill level... so If it Requires major Surgery to shove a big block in then a SBC will serve just fine (built right ) Its a CJ nosed Commando so any of Y'all that have big blocks in a CJ yr input would be appreciated... small block swaps 2! The more info the better!

Oh final plans for the build also include 37in Humvee Tires... I want low gears... but I want to be able to run 55mph at under 3k RPMs with a 3-speed auto. TH350-400 to be exact. Would 4.56s work for this combo or should I go with 4.10s??

[upsidedown]

4.56 gears will get you where you want to be under 3k rpm's with the 3 speed auto. If you go to 4.10 you will be luggin with the 37's.

You could get a newer chevy / GM out of a 4x4 truck with the engine, trans, computer, wiring harness for about 2k. The 5.3L in the newer trucks makes 310hp and 320ish tq. Very reliable and fuel inj. and light weight if alum block. Just a thought.

Your build sounds cool. Jeepsters are classic. Good luck.

[SanDiegoCJ]

Go with a small block. Cooling a big block is tough in that tight engine compartment.
You'll also need to get the bellhousing for a BOP or an auto with that pattern to bolt it up to the motor.

[C4ptnCh4os]

Originally Posted by SanDiegoCJ

Go with a small block. Cooling a big block is tough in that tight engine compartment.
You'll also need to get the bellhousing for a BOP or an auto with that pattern to bolt it up to the motor.

I already mentioned that I would be using a TH350/400. Either a 350/350 combo or a 455/400 combo... that way I don't have to worry about custom adapters & rebuild is cheap (450 bucks).... I am worried about the cooling issue with the big block tho. Im also worried about that issue with a small block... would a standard 4 core radiator fit in the engine bay?? I'm planning on using electric fans so I know that gives me a little extra room...& what is the difference between cooling requirements for a big block vs a small block???

[BarfBag]

I had a complete brain fart and put an Olds 455 into my 69 jeepster. It bolted to my transmission, th400, with only minor trimming to the factory adapter (the starter for the stock 225 is on the other side) It is a huge chunk of iron, I had to trim everything off the grill, notch the headlight buckets, put the radiator right against the grill, use a low profile electric fan and still had to move the tranny/tcase back 3 inches, which required significant firewall modifications.

As soon as I have time for another project, the 455 is coming out and a 5.3 or 6.0 is going in.

I still wonder how I managed to do something that took that many hours without coming to my senses first.

[BarfBag]

I forgot to mention, the 225 that came in the jeepster can be made to put out decent power. I installed an Isky cam (dont remember the specs, it was 15 years ago) and a weiand intake with a 390 cfm Holley. After messing with the carb for a bit (jets and springs) it would light up 31 inch tires (15 years ago they were common) with stock gears and an automatic transmission.

I should have kept the 225, but brain fart got the best of me.

[C4ptnCh4os]

Originally Posted by upsidedown

4.56 gears will get you where you want to be under 3k rpm's with the 3 speed auto. If you go to 4.10 you will be luggin with the 37's.

You could get a newer chevy / GM out of a 4x4 truck with the engine, trans, computer, wiring harness for about 2k. The 5.3L in the newer trucks makes 310hp and 320ish tq. Very reliable and fuel inj. and light weight if alum block. Just a thought.

Your build sounds cool. Jeepsters are classic. Good luck.

Thanks!!!
I know 4.56s would get me where I want to go... but I NEED to be able to run 55mph... when Im gone at school with my pickup my Dad will need the Commando & our hillrod trailer to get Hay & saw dust every month for our horses & its gotta be able to run down the by-way to get there so will 37in tires & 4.56 gears allow me to do THAT under 3k rpm??

I would LOVE to do a 5.3 or 6.0 swap... my daily driver has a 6.0L & I love it!! but this is a budget build & I want to put in parts that I know will be easy to replace if I break something. I can build a 350 with nearly 400tq for less then 2K & a Heavy duty 350 rebuild costs me $450 thru a local trans shop.... another reason I want to stay away from a 6L/4l80e combo is all of the wiring... I do like fuel effiency tho so a TBI setup is in the works & wiring for that isn't too terrible

[C4ptnCh4os]

Originally Posted by BarfBag

I had a complete brain fart and put an Olds 455 into my 69 jeepster. It bolted to my transmission, th400, with only minor trimming to the factory adapter (the starter for the stock 225 is on the other side) It is a huge chunk of iron, I had to trim everything off the grill, notch the headlight buckets, put the radiator right against the grill, use a low profile electric fan and still had to move the tranny/tcase back 3 inches, which required significant firewall modifications.

As soon as I have time for another project, the 455 is coming out and a 5.3 or 6.0 is going in.

I still wonder how I managed to do something that took that many hours without coming to my senses first.

THAT ^^^ is exactly what I was afraid of... all that fab is definitly out of my skill level... looks like a TBI 350 for me! Don't get me wrong I love the 5.3/6.0's... just don't have the money for em...

[osubeaver]

Here's a guy on the Jeepster forum who put a BB in a Jeepster. It's not the greatest build thread because of not too many pictures. It does show that it can be done. I'm just not sure why you would though...

http://jeepstercommandoclub.com/foru...hp?f=9&t=11561

[C4ptnCh4os]

Originally Posted by osubeaver

Here's a guy on the Jeepster forum who put a BB in a Jeepster. It's not the greatest build thread because of not too many pictures. It does show that it can be done. I'm just not sure why you would though...

http://jeepstercommandoclub.com/foru...hp?f=9&t=11561

After doing a little more research I don't think Im going to go the BB route... too much work... this is supposed to be a failry cheap project for my Dad & I & a 350 should suit our needs just fine

[sixshooter]

If you are worried about running 55MPH, look into a later model 231 buick motor, mid 80s. If you want to get really creative, look into a T-Type or Grand national or just a turbo regal motor with a turbo on it. I was looking into those combo's and the parts are not that expensive as there is so much aftermarket support out there, the parts are an easy come-by. I have driven a 252 buick V-6 in a monza with a 4barrel and a cam, and ran like a small v-8. The 225 is odd fire, and the 231/252 is even fire, but there are ways around the flywheel, convertor, etc. You could also look into using a 3800 supercharger from a grandprix 3800...I am a big advocator of using factory go fast parts and making them go fast on my old school cars. It will take some fabrication work to do any of these things, but you will have a reasonable economical vehicle that is fun to drive. Good Luck

[#1COMMANDO]

Is this commando an automatic or a manual? Is it a v6? Because if it is an automatic and a v6, it would be better to use a small block buick, pontiac or olds because it will fit to transmission and you will only have to make motor mounts and trim radiator support for clearance alot easier than a chevy swap.

[Missoula4x4]

Looks like this will be a fun project. I wanna get a commando too and do the CJ front end, SBC, SM465, Dana 44s or Dana 60s, SOA, and 37" Humvees. Keep us updated and post pics. Project like this definitely deserves a build thread!

[strvger]

if your commando comes with the v6, let me know how much you want for it!!