I have a 1997 sport that has 222,000 thousand miles and the motor is on it's way out. I have a 89-90?? long block that I was thinking about rebuilding with some mild upgrades such as a cam, some mild porting, maybe larger intake and exhaust valves higher volume oil pump, nothing crazy just a little bit more reliable power. my question is what is a better idea rebuild the earlier motor or pull mine and do it? Or hunt down a head and a block. From what I've read and all I have really done is read on here. Later blocks are better but heads are not, seems there has to be a good combination of head and block combo to do the best complete engine build on, I want to start with the most solid platform I can

Opinions please!

 

It all depends!!!

Money, time, and whether or not this is your DD.

V/r,
-Gray.

 

my budget is probably from 1700 to 2200 depending on what performance parts I do, my time frame is wide open and I have a tacoma I can drive if the jeep is down the jeep is my DD my 2008 tacoma sits in the garage. lol. could I do a mid nineties HO head like 93-95 with a later 00-01 block? I plan on doing the later model intake as well when I do the rebuild. any problems with that combo between say with like ignitions, sensors or anything? thanks again

 

I have recently completed almost exactly what you are thinking about doing. I have a '97 which had a cracked block, so it had to go. I took a '95 block and rebuilt it to nearly factory '97 specs. I used the '95 block, rods, and head. Then replaced the cam with the later dual patteren cam ('97 spec) with lifters, bored block 0.020 over, Sealed Power pistons to fit, all new bearings, gaskets, and seals. While at it I also installed the '99+ intake manifold, banks exhaust header, and Chrysler 703 injectors. Along with this I replaced several parts that bolt onto the motor- Harmonic balancer, flex plate, thermostat, water pump, hoses, fluids, cap/rotor, plugs/wires, belt, air filter, oil and oil filter, temp sensor, and probably a few other things I can't think of right now. I have well over $3K into just the motor and items mentioned above.

So when people tell you that you can rebuild a motor for under $2K, they're sort of not telling you the whole truth. It was very difficult for me to spend this kind of money, but I'm hoping that in the end I'll come out ahead. All I can tell you so far is the "break-in" went perfect and it's running strong, but I have not driven it yet.

You could use the '97 block, but I don't think using the renix motor would be a good idea, I would even recommend staying away from it.

 

I have a JY in town with a 95, complete motor, and a 2000 complete motor I can get either for 3 to 4 hundred depending on the guy I deal with, I already have the 703 injectors, and a header, and I get the machine work done for free. that is why I set my budget so low. I'm just after the "dream combo" or best year to start my build off of.

 

Have you been to jeepstrokers.com good info there, especially about heads and such.

 

I have not, But i'll check it out

 

The 95 block would be better IMO, mostly for the reason the 2000 head is prone to cracking and the 7120 head is said to "flow" better then the 0630 head on your '97. Add to my list of things I replaced: motor mounts and fuel pump. If you're going to spend some serious coin on the motor don't forget about the other important things on your vehicle that need attention, especially with 220,000 miles on it. While I had my motor out I also serviced the transmission and put in all new o-rings.