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I have a 54' with the original 235 engine it. One thing I am considering is an engine swap to a more modern engine. Has anyone done this? What are the pros/cons. What else needs to be updated, etc.

I have some mechanical abilities but am by no means an expert!!! Just doing research at this point and looking for thoughts/suggestions.

Thank y'all very much!

Why are you considering a modern engine? What do you plan to use the truck for?

And yes, thousands of people have done it. Thousands more are happy with the stock six, maybe beefed up a little.

The truck will mainly be used for pleasure.

Primary reason for considering newer engine is time expertise. As much as I would like to play around and figure out/upgrade the original motor, I have just opened a business and work 16-17 hr days six days a week. Not much time for a hobby right now.

Also, the current engine is not running (likely a fairly simple fix e.g., bad gas from sitting, carb adjustment) and I don't have time to work on it.

Another reason is that our family is down to 1 vehicle right now so having the truck as a second, usable vehicle would be very helpful.

Finally, I live in a very remote, small time (pop less than 1,000) so finding someone with the expertise to help with the 235 is not easy.

Bottom line for considering an upgrade is time right now and limited local expertise (myself and others).

Carmen, under your situation would it be better to have your truck towed to a trusted mechanic some friend recommends....get the truck running first, if it will run, drive it and then decide what you want to do, if anything.

I understand the 16-18 hours a day. Did my share. Its probably better to keep working and pay someone else with the expertise to get it going rather than spend money on it if your not totally sure at this point.
That said there are almost to many options to even try list. With your model truck though there are some "updates" that are surely easier than some on the earlier model trucks!

We're here to help. Think about and ask questions...and there are a LOT of Texas Bolters. It'd be nice to fine one near you so keep watch.

If the engine problem is minor, you should be able to find someone to get it going much quicker than having an engine swap. The old bolters just need gas, air and spark and they are good to go plus they are easy to work on.. I've seen 235's sit for years and an afternoon of tinkering has them running like a Swiss watch. There must be somebody in your area that can do the work.

Thank you for your comments & suggestions. I do have a few more questions. Since this is our second vehicle and the nearest "large" town is 75 minutes away I would like to use the truck to make "supply runs". Can a 235 be tweaked to get highway speeds (70 mph here in Texas)? And if so, do I need to upgrade anything else - brakes, transmission, steering, etc. Just curious. As I said I am new to this and trying figure things out.

A little background. The truck was named Carmen by the previous owner after the Portugese born Brazilian singer Carmen Miranda. I haven't thought of a better name yet, so for now she remains Carmen.

The truck did run several years ago when I purchased it. However, my son used it for a few days and... Nuff said! We got busy and truck sat for a few years. The engine does attempt to turn over, just won't catch. That is where I am today. Just haven't had the time to tinker.

Thanks again for all the input. It is greatly appreciated!!!

To get it to run 70 you will need a higher geared rear end. There are no aftermarket gears for the 3/4 ton. A later model 4.10 will swap in but they are hard to find and that is still pretty low gearing.

Your brakes might be adequate but front discs would be a comforting upgrade.

Carmen;

I have to pile on with Alvin and the others. I had the same thoughts as you when I bought my 58 Suburban. It does not have the original motor, but it does still have a straight 6 250. It ran pretty rough when I got it so I was convinced I would need a newer/bigger/better engine. I had visions of a hopped up 292 dancing in my head.

Well, a real good carb cleaning, setting the timing and addressing a vacum issue was all it took to get it singing. I have plenty of power to pull the big old beast around.

Get the 235 running and you will be satisfied. As was said above, gearing is the key to highway speed. You can either change the rearend or change the transmission to an overdrive unit. You can get some return on going to taller tires, but not a whole lot.

Bottom line: for a relatively minor investment I think you could get the 235 running and be very happy with the results. It's a lot easier to have philosophical debates about the future plans for your truck when you have it running and can use it. Gives you more time to think. Now if it turns out that your son toasted your motor, that is a horse of a different color. Oh the joys of parenthood. :-)

The Vortec 4200 is becoming a more popular swap. If you aren't afraid of a modern engine. There's tons of Trailblazers and Envoys showing up in the scrapyards now, so finding a donor isn't going to be hard to find. The 2002-2005's had 270 HP and 270 Ft. lbs. Not to shabby on an inline. The 06-09's had 290 HP and slighly more torque. The only trans that was ever offered was a 4l60e. There are guys that have made adapters to fit 4l80's and earlier transmission.

If you go to the Inliners site, look for EFI-DIY or Limequat. They can point you in the right direction.

One more thing about the Vortec 4200, it's the exact same length and hight as the 235, and only a little wider. If I ever swap out the 235 in mine, and don't go for a 261, the 4200 would be my first choice.

So with the Vortec 4200 you get a good power boost and you can still look yourself in the eye in the mirror by keeping an in-liner in your truck. Very interesting.....

I might be rethinking my position on a 292 if I ever decide to jump to a bigger motor.

I agree, find someone to get the existing motor running. Then I would look into a trans swap and final gear swap to get you into the 70mph range.


EFI-DIY has an ATLAS powered 'bolt on here. (ATLAS is the name GM gave to the line of engines that contains the 4200 and all smaller versions)

with a bit of tweeking your well over 300hp with the 4200. as for a manual transmission, while the 6-cylinder did not come with a manual, every 4 and 5 cylinder ATLAS motors did. use the bell housing and flywheel from the 5-cylinder and you get capability to put a manual trans behind it. Westers garage up in canada can reprogram your ECU or provide a reprogrammed ECU to run the motor with any trans behind it.

New motors and old motors are pretty much the same. if you dont have time to work on them, they dont run.

I also started a thread in the Texas bolters section. I agree with y'all and think my first priority should be to get her running. That said, we were not very busy last year during spring break so we closed the restaurant this year. I have some free time :thumbs_up: and would like to do some trouble shooting. Any suggestions about where to start would be greatly appreciated! [url=https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=926901&#Post926901]Link to thread[/url] <--- not sure why this is not showing up as a link...

Here is the other thread.