Hey guys... I would appreciate some advice on an engine dilemma that I have. I have a 98 3/4 ton 4x4 that currently has a 5.2 engine in it with a known 95k miles on it. This engine is not original to the truck but has been in it for the last 2 years. I just recently bought a 5.9 that has unknown miles and condition but has EQ heads with stainless valves. The heads have been on the 5.9 for about a year (receipt dates). I guess my questions would be...

Should I put the EQ heads on the 5.2 or do I take a chance on the 5.9?

How much power difference is there between the two?

Currently there are no other mods done to the truck except the plenum fix. I would however like to put on some shorty headers and replace the "y" pipes when I do this engine work. The truck is basically a daily driver and I tow with it on occasion but it's only a vw on a car hauler trailer.

Thank you very much for any advice or comments you are willing to share.

Brian

 

Others here know a lot more than me, but from what ive read here there is not much of a horsepower or torque difference between the two engines. I would just swap the heads and call it good.

 

Thank you Ram Driver. That's kind of the direction I wanted to go. I just wasn't sure how much difference there was between the two in power.

Brian

 

5.9 thats a given. Has a comp test been done on either motor?

 

No compression check on either engine. The 5.2 runs decent, it just uses coolant. I basically bought the 5.9 for the heads. It rotates freely on the stand and doesn't appear to have excessive junk inside. I just don't really know much more about it.

 

A 5.2 is a mighty small motor in a 3/4 ton truck, especially when towing or hauling a heavy load. I would not hesitate to put the 5.9 with EQ heads in that truck. Must be a reason the EQ heads were put on the 5.9 - likely to cure the coolant leak issue you're experiencing with the 5.2 (cracked head/blown head gasket)...

 

Me I would take the gamble and install the 5.9. Probably less time to install it then swapping the heads.

 

The previous owner replaced the heads due to cracks last summer. Later he decided to make his truck into a rock crawler and takes the 5.9 out and puts in a Chevy 454. I saw his truck with the 454 in it and it almost looked like it was supposed to be there.

 

By myself I can swap a motor in these trucks in 6 hrs. When I changed the heads with the motor in the truck, every last thing ready parts wise it was close to a 15hr job. You might be able to cut some time of that head swap as I have a F***** neck and back.

 

Looks kike I need to dig into the 5.9 more.