I know it's been covered a million times, but I just wanted to run a few things by you guys. I'm very familiar with the 5.2->5.9 swap in Grand Cherokees, and I'm assuming it's the same in Rams.

The motor in my father's 98 1500 went out. He bought what he was told a 1999 318 with 75,000 miles. Apparently now that the motor is sitting in the truck, they found out it's actually a 360 (I'm not sure how they verified this.)

Needless to say, he's not happy. I told him to upgrade to a 360 in the first place, but he is convinced he'll get even worse gas mileage, and that he wanted to keep it original with the 318.

Anyways, they obviously used the flex plate and harmonic balancer from the 360. I told him to use all the sensor from his 318, and that it will run with his current PCM but it will run lean and to look for a PCM from a 360 truck. Anything I missed?

 

Nope sounds like your good. Take an accessable plug out and look in the hole. 360's have dished pistons 318's don't. It should be easy to see.

 

Not trying to spam or anything but if his truck is an auto I can sell you a pCM for the 360 I bought for mine but mine is a stick so it wouldn't work

 

Send me a PM with the PCM information (year and number off the tag if you would.)

So an update: They fired it up and apparently it runs good, but after talking with my father he thinks they took the flex plate and balancer from his 318. He's not 100% though. He also thinks it has a slight miss, but he also isn't 100% because he didn't have time to hear it run for long.

My father is very mechanically inclined, but didn't have the time to do it himself so he's having some mechanics at his shop do it which is why he's so unsure of what they did. Correct me if I'm wrong, but won't an unbalanced flex plate cause a miss in the engine?

 

wont cause a miss it will cause it to feel like it's missing

 

Yeah, I guess I should have been more specific. I know it won't actually cause a miss fire but it will feel/sound like it is missing.

 

then yea lol you answerd your own question brotha

 

Yeah lol. Like I said I know the swap pretty well, I just wanted to check with you guys to be sure I'm not passing along any bad information. He's down in Florida, or else I would have been the one performing the swap.

 

UPDATE: They used the correct balancer and flex plate for the 360. Turns out the miss was a bad plug for the #2 injector. When they wiggled it around the miss went away and the engine purred like a kitten. He's still not happy about having a 360, but he did say that the extra power is nice.

Thanks for the help guys!