Hello and good afternoon. I just bought a 03 ram with blown motor but not seized. I took it apart and found both rear connection rods for the pistions broken. My question is what are my options as fars as other engines that will fit. Ive priced gen 3 5.7 engines that are used and would like to see what else would be ideal to go in with. From what ive read 03-05 5.7 are the same. Any suggestions with differant engine and what are the challenges you have faced. Thanks in advance.

 

Did it originally come with the 5.7? If so, then, I *think* you can use up to an 08 motor. (a bunch changed in 09.)

 

Yes. Its a 5.7 from factory. But after 05 they intergrated msd for active fuel management but the motor for gen 3 is the same to a point from 03-08 from what ive read. Not sure how or where it differs but it is after 05

 

MSD (Multiple Spark Discharge) is an aftermarket ignition system. MDS (Multi Displacement System) is strictly for fuel economy; wouldn't call it active fuel management because technically, basic computer controlled fuel injection is "active fuel management" lol. 03-08 5.7 are basically the same with a few differences. 03-05 don't have MDS. 03 has does not have EGR, but 04-05 do. 06-08 1500 engines only have MDS and EGR. 06-08 2500/3500 do not have EGR nor MDS. Any of these will drop right and bolt to your truck and transmission. If you use an 04-05 engine you will need to plug the EGR hole on the head and the intake manifold (depending on which manifold you use). 06-08 1500 engine you can run as is; default position for MDS is off, so as long as you leave the solenoids in and unhooked it'll run just fine. If you pull the solenoids without replacing the lifters, the existing MDS lifters will collapse, leaving you with about a 2.9L four cylinder running like ****. 06-08 2500/3500 engine will drop right in.
Another option you have if specific truck engines are hard/expensive to find are the 05-08 LX (300/Charger/Magnum) 5.7's. They all have MDS and EGR, but that's the least of your worries. You would have to swap oil pan, intake manifold, front timing cover, starter and dipstick to get it to work correctly in a truck; otherwise they are fundamentally the same engine. The 05 LX 5.7 even has the same wasted spark setup the trucks have through 05.

 

Ok thank you for the details. That helps alot.