helnbk

I'd swap it for an LS engine if only for the weight savings and possibly better MPG's.
Our Jeeps are heavy pigs anyway, and that hurts us offroad on a lot of obstacles.
But only go the LS route if you plan to keep it for the next 5+ years.

BoogieMan

IMO, go for the 6.1 Hemi. Because you can later on purchase 426 stroker kit. With the tranny, I would go with an T-56 Magnum (6-speed manual). From what I was told, that the tranny torque capacity is about 700-900ft-lbs.

Fan45acp

LS1,2,3,or LS6... with the 6 speed auto...

big dr

There is a company called CBM (custom built motors) in so cal. They put a lot of LS1's in a lot of vehicles. They are very good at customer service and would answer any questions you might have if you are considering this option. Check out their web sight

Earth Siege

To my knowledge all LS numbered motors are aluminum block, all size numbered motors are iron block
Example numbered blocks
Ls1,ls2,ls3, ls6, ls7, ls9 (the ones not listed are for front wheel drive cadilac builds)

Example size numbered blocks
4.8L(which doesnt have cylinder shutdown), 5.3L ( does have cylinder shutdown, 6.0L (doesnt have cylinder shutdown)

The ls2 and the 6.0L are basically same engine except that ls2 is aluminum and has cylinder shutdown enabled

There are rare 5.3L engines that are available as aluminum block, they have a special call code like LKQ or similar(its available info on wikipedia) but most are iron block

The numbered blocks are reserved for truck builds due to aluminum cracking under heaving towing and vibration issues in 4wd (under heavy loads). Also the iron blocks allow for more size options than aluminum since iron can be shaved thinner in the sleeves and still have more strength than aluminum.

However i would look for an LS BASED OR rare 5.3L aluminum block anyway and put into jeep for weight savings- i dont tow and it seems the ls motors also tend to get better mpg due to cylinder shutdown

OJK12

This is an interesting thread, ultimately it's up to you what you want but I'll give my .02. I'm not a Chevy fan at all, it's Mopar or no car at my house and I deffenatly bleed blue. To me the hemi makes more sense, they make more HP, they make more USEABLE HP as in like peak at 4500 RPM instead of 6000-8000 RPM, they are very durable, and they also come in aluminum blocks. The current gen hemi also gets better MPG. To me the only real advantage of aluminum is the weight savings. Aluminum blocks tend to be weaker and need more maintenance. If your never gonna supercharge, stroke, or beat on it the aluminum will be great but and old iron block will take better long term abuse, that's why the truck engines regardless who makes them are iron not aluminum. The only drawback to the hemi is the cost, Mopar makes it very difficult to do engine swaps without costly wiring harnesses and custom ECU reprogramming or other costly features like the chip killer distributors. The Chevy may be a cheaper turn key setup. Everyone has good points and bad all I can say is good luck with your choice and keep us in the loop.

ridelots24

thanks for the fair assessment. I should have said at the top, the cost is so close to each choice, not really a factor in my decision. Just trying to pick one that i'll be happiest with for next 7+ years..... if only i gave my marriage this much thoughtful consideration.....

cfr

Slightly used 3.8 from one of the hemi-swap shops and a RIPP supercharger?

nmzj

Have you looked at the jeepspeed kit?

big dr

"""thanks for the fair assessment. I should have said at the top, the cost is so close to each choice, not really a factor in my decision. Just trying to pick one that i'll be happiest with for next 7+ years..... if only i gave my marriage this much thoughtful consideration...."""
hahahahahah
Great quote!