could anyone please assist with advice and where to source the right parts for my swap, 2007 H3 3.7 to 5.3 V8 hummer powerplant. I have purchased a 2008 5.3 from GM, tranny mods done and electrics need assistance and lots of advice. I'm determine to complete this poject.

 

Nice one....I know a place but not local for you....Im in UAE and have just replaced 2008 3.7 with 5.3 likewise......finished and picking up sat.....for some road use before hitting the dunes next week......will then see how the new FOX shocks go as well....

First advice.....be patient
Make sure the wiring is done by someone good, this was the biggest issue we had was getting everything to intergrate into one system and recognise all codes etc.....and my guys are very good at what they do.....
Will also need to do exhaust........ive also got an additional fan infront of the radiator...(dont know if thats standard or not in cooler countries? sure someone will say) gets very hot here 55C = 130F + in the sand in summer.....

good luck, hope it goes well.... ignore the naysayers....lol....

 

Wow... I would have guessed it to be cheaper to buy an Alpha rather than do a conversion... but what do i know ?

 

Thanks Sandkiwi

I would like to get in contact with them. Yip in SA we it also gets very hot 35C to 40+...the last thing to worry about is the exhaust. The wiring and getting the system intergrate and codes recognised. I need more info on this which harness, where to purchase, ect...

 

I believe the alpha had many modifications to accommodate the larger engine which included an entirely different firewall that extended closer to the dash, reworked front framerails, as well as needing a special low-profile oil pan.

 

yip agree, but I need info and detail on the wiring harness and all electrics

 

Pm hummech here on the forum. He should be able to source the parts for you.

 

will do perhaps got some contact details?

 

Is it possible to replace the I5 with anything bigger than the 5.3L?

 

Yep.....comes down to money and whether you have someone you trust and also knows what they are doing (2 different things)....

I was lucky my 5.3 was taken out of an alpha to put in a 6.0 as the guy (A local Sheikh (Ruler)) wanted more power....so I got his near new 5.3 engine.....so it can be done. Electrics will likely take the longest....

Do it and get a pro performance tune at the same time, you wont know the truck....

And as said already......ignore the nah sayers.....lol....