My 17 year old son has a 1998 Dodge 1500 SLT 4x4 with the 360 automatic. Now the engine is in really good shape with 90,000 and leaks nothing and burns nothing. Problem is its a dog. We have had it tuned up and everything but he is getting about 10 mpg and pretty crappy performance. The only mods are dual exhaust and a cold air intake.

I am not against throwing a new motor in there for him to give him more towing power, he tows a 24 trailer with 4 atvs. Hard to tow that more than 60mph.

So can someone recommend a good crate engine for this truck or would it be best to have someone rebuild it. Looking for at least 300hp and 300+ tourque.

 

Chances are the kegger intake plenum gasket is leaking &/or the cat is going
What size tires & gears does it have?

 

Rebuild as a 408. Make sure you do the plenum repair. Information on the plenum repair can be found by searching. The 408 builds have been discussed a lot also. Welcome to Dodgeforum!

 

fix the plenum, delete the cat, that should fix his problem

 

Do all over the above and invest in some 4.10's for towing.

 

I can easily rip out the cat and replace that with a straight pipe. But at the risk of sounding like a dumb a** what is the plenum and how much will it cost to replace? Also what would should I expect to pay to have 3.55 switched over to 4.10s

Thanks guys

 

Is your truck a 4x4 or 2wd? If your truck is a 4x4 you are looking at 2k. (I'm in the same boat but I'm going 4.56 ) Please edit your sig and give us some more info. Year make model motor ect.

 

410 gears on stock dia tires good for towing, if he has 33 or bigger, best to go with 456gears IMHO.
Plenum gasket is underneath the intake manifold. Crap Dodge design has alum intake with a steel plate beneath it that causes the gaskets to shear due to different expansion/cooling rates for steel & alum. You can get an alum plenum plate & gasket to fix the design flaw at Hughes for 86 or get an M1 or F1 intake that will elimate the gasket completely(FI isnt cheap).

http://www.hughesengines.com/Index/p...keyword&page=5

 

Thanks guys, his truck is a 1998 4x4 with the 5.9 in it. He has normal stock size tires nothing has modded there. Again the truck doesnt leak any oil but sure seems like it should have way more power. to my knowledge this gasket has never been replaced, could that "leak" be causing a power lose? He has told me that it does knock a bit at times.

 

Replace the gasket and invest the $2,000 for gear. Change all fluids as well. Motor tranny both diff ect.