Replacing 7.4L (L29) with 5.7L (L31)

[Supercharged111]

Thank you all for the wisdom.

We've convinced you to just get a big block now, right?

 

[xXxPARAGONxXx]

We've convinced you to just get a big block now, right?

Yeah. I posted here for insight from the experts, and that's what I got.

I have a Jeep Wrangler JKU. I'm trying to sell it, as I need a truck. Not a new one. Can’t afford those, and honestly, I’m not sure of the reliability of the newer engines compared to the L29 and L31. But, reliable or not, it’s not in the budget.

I’m looking at the GMT400 K2500 (98-00). My only area of question was the engine.

I like the reliability of the L31 and the gas mileage. But, @someotherguy is absolutely right. If I was driving a 1500 with the (1) 5.7L, (2) 4L60E, and (3) 8.5" 10-bolt rear, then gas mileage would be better than the (1) 7.4L, (2) 4L80E, and (3) 10.5" 14-bolt rear.

However, pairing the 5.7L with the 4L80E and 10.5" 14-bolt rear, the gas mileage of the 5.7L will be worse than the 7.4L. I guess I had my mind on the 5.7L but needed the wisdom and guidance from the experts to set me straight.

I appreciate that. Thank you all. Wish me luck.

 

[someotherguy]

Get the truck you need to do the job you require of it, and the MPG won't matter.

Get the truck based on MPG and not the job required, and the truck won't matter because it won't do the job you need.

Richard