I have a 2009 H3T, 5 cyl vortec. I can't stand this engine, it's noisy and underpowered. Should of purchased the 8 when I had a chance but its to late for that, now I want to see if I can purchase a new 5.3 from GM and drop it in. My mechanic said that I don't want to do that and it would be better to purchase a new pickup truck, but I love the truck. Has anyone had a experience with changing the engine? Do I have to change the Trans? What else needs to be changed? I cant find a alpha for less then 35,0000. According to KKB my truck is worth 22,000.00. Any suggestions

 

my guess,,,btwn $20000/$30000, after all the smoke clears

i had a chevy s10 with a 4.3 v6, now there was a tire spinner,for you!

years ago an engine swap was a few mech adapters, gas line and a few wires. today,i doubt if many people can do it.
its a gigantic undertaking
tom

 

Thanks, I was afraid of that and I don't have that kind of money. I figured it would be huge when my mechanic turned it down. I guess just another one of lifes compromises.

 

Do the trio of a dual catback exhaust, an Airdoc CAI and most important a PCMforless tune. I have owned a 3.5 a 3.7 and now a 5.3. I had the 3 mods done on the 3.7 and it was a little screamer. In some ways I liked the performance of the the modded 3.7 better than the 5.3 in the Alpha. The exhaust is the most expensive but if you have a good local muffler shop they should be able to do if for half the price of a pre-made. One more thing, I added the Alpha intake snorkel to the Airbox and was surprise at the difference in pickup. Do a search on this forum and you will find a lot of information on these mods.

 

As a pro in the industry, I too would suggest either modifying or enhancing what you already have, or just changing vehicles to one already equipped with the 8.

It is not that an engine swap could not be done, it is that the cost, time and grief you will go thru to do it would be nearly impossible to justify.

It is not just a case of bolting in an 8 cylinder. You will have wiring & ecm to contend with at minimum, and if it is not done right problems will occur.

Off the top of my head the only concievable way it may be worthwhile is if you found a wrecked v8 model identical to yours that you could get all of the electrical & drive line out of it that you would need. Then you still have to contend with installing it as well as how it may have changed your resale value of it. If you should go to sell it, it may become a hard sell with the engine being an after the fact swap even though you may have used all of the same stuff.. Just my 2 cents.. J

 

Thanks guys (girls) for all the great advice. I looked into the exhaust, I tow a 3,300.00 pd boat with a 800. pd trailer, add fuel I'm close to limit, ishe pulls the boat fine but she's always searching for a lower gear. My mechanic said that the exhaust will help on the the high rpm for better breathing and add speed but will lose torque and hp on low rpm, which is where I need it. He said that a program adjustment for the computer for better tow settings may work, so I'm may looking into purchasing one. I love the truck and don't what to sell it, I would trade it in but there only one new H3t in the country (according to my dealer) that qualifies for the 72 mo 0% interest and the guy wants 52 K. Thanks again

 

This is not that hard to do and alot cheaper than buying a V8 hummer. You should be-able to do this for about 5 grand if you shop around a bit.

Check this out it is a colorado but, very similar, and based off the same platform as the H3. At the end of the thread you will see a list of possible parts needed.

https://www.hummerforums.com/forum/o...ou-guys-23952/

The trans won't directly bolt up, automatics just have to swap input shafts, bell-housings, torque convertors.

Ma5 manual needs new fly-wheel clutch, advanced adapters bell-housing, trans spacer, and a few mods here and there.

06-07 hummer should use E40 PCM and 24x ignition motor.
08-12 hummer could use E67 and a 58x ignition motor.

You can go either way, but sticking with the above rule is the easiest.
in 08 hummer changed the fire wall, and frame rails for the V8 making room for a truck style intake. The older models will work still, just use the car style intake manifold.

Current performance, makes engine mounts (called colorado LSX mounts) should also work on the H3 hummer.

I offer wiring harness, etc

 

Thanks for digging up every old engine swap thread on this forum. I see you are trying to SELL us something but it seems you don't know much about GMT 345s (our HUMMERs) not 355s (Canyon/Colorado) . You may want to do some research before stating anything about options for swaps, cost of an Alpha over an I5, etc.

 

Please tell me how to edit a posting?? I would like to remove anywhere were it says I can build you a harness.

If a Mod does this than, I would depreciate leaving up the other info, as it is useful to people, and does not benefit, me in anyway!

Also I removed the words in my sig, until someone let's me know if that is ok or not! Again sorry, and no need to nail be to the wall I honestly didn't mean to upset the apple cart, and offend you Tainter! My name is Jamie, and maybe you will forgive me, and teach me all I want to know about 345, some day!!

 

Just an FYI, it is widely accepted on just about every forum in existence that reviving old threads with a new post is frowned upon, especially doing it to multiple threads across the entire board.