258 questions

[matt0481]

I am swapping a 258 into my '79 WT that had a V8. The engine mount brackets are spaced from the firewall differently for the 258 vs. 360. What has to be done to compensate? I revived a 258 from my newly aquired '76 Gremlin for this project. It sat for 11 years until today. It ran perfect! I replaced the freeze plugs and water pump as insurance.

[Cecil14]

Just curious why you're going to the 6? It'll be a lot more work than swapping in another V8. That said this is what I know:

You'll need a different motor mount for one side I believe. The other one should work from what I've been told, might need to use a different set of holes though. The 6 sits farther back so you'll need to use the rear set of holes for the tranny crossmember. You'll also need a different set of driveshafts. Everything else I think should bolt up...starts should be the same, fuel line you may need to reroute and maybe some electrical wires, too.

Somebody else should catch anything I missed...

Anthony

[matt0481]

The Gremlin was free and the AMC 360 was dead. I have all of the needed parts from an '84 Wagoneer w/258.

[Cecil14]

Free is a good price. If you've got all the parts it shouldn't be all that tough a swap. For the motor mounts just grab the ones from the '84 and there should already be a set of holes in the frame. Like I said before, I think one side stays in the same spot but the other side has to be moved. If you need to drop the motor into place on a hoist and figure out which holes to use that way.

Good luck,
Anthony

[matt0481]

I want to say that I saw a weld on the frame brackets. I looked on both rigs and they had a weld on the top of the brackets. I didn't see the other mounting holes either. What gives?

Thanks

[Cecil14]

Hmmm...I'm at a loss...I can see them putting a small weld on the mounts at the factory to keep them from moving...but I thought there was suppose to be holes for both set of mounts. AMC was fairly generic in most of their stuff and usually just used one mold. One frame fits all kinda thing...I don't know.

I hope I didn't give you miss info, didn't mean to. Somebody else chime in here?

Anthony

[matt0481]

It doesn't seem to be a large weld. I measured from the firewall to the center of the motor mount bracket. 15" for the V8 and 13" for the 258.

[Cecil14]

As for the weld if it's just a tack weld or a small weld to keep the mounts in place, just grind it off. It shouldn't hurt anything. You said there were no other holes, right? Are the mounts different for the two motors? Maybe they cast the mounts different to compensate for the different positions?

Anthony

[Crazy_Jeepman]

The Frame towers are different, or so I always thought. I doubt that moving them will do you any good if they are for the V8, you will need the I6 frame towers. The weld is easily ground off, remove the bolts that hold the frame tower and shock mount in place. The second set of holes do exist, look they are there. I take it your 79 has an Automatic, you will need the flexplate for the TH400 and I6 if you already do not have one.

[matt0481]

I've got a 727/NP228 to use instead of the 400/QT. Front axle already taken care of. Yeah, the towers are different. Now I have to drag the smoke wrench to mom's to get the 258 towers off.

[Cecil14]

Do you have an angle grinder? That'd probably be easier, and you won't eat the frame that way. Torch'll of course do though. smile.gif

Anthony

[phil a]

The welded mounts- instead of bolted- may be, that all WTracks had V8's??? Yes, the holes should be there, or at least a dimple to center punch.

[matt0481]

I'll probably see them when I pressure wash the chassis.

[sloop]

Remember to swap flexplates, you'll need a flexplate for a 258-TF727 combo. According to the IFSJA Drivetrain Database, you should be able to buy a 258-TF727 flexplate for a 1980 Wagoneer, since that year had the 258 but not the TF999.

[Wagoneer622]

Phil a: my fathers 79 W/T had a I6 in it stock according to the vin#. I am pretty sure they were available with I6's.

[matt0481]

I got the flexplate from a '84 Wagoneer w/258. Same for the towers. Guess I'll grind them Saturday.

[porkchop]

Hey, Matt, remember if you need help I am 30 minutes away. I have Duty this saturday but will be available on Sunday and then again Tuesday and for the rest of the week. Just let me know. My number is 910-324-6821