327 to later model AMC trans adapter

This is my first time posting. Currently, I am in the process of swapping a 68 Jeep 327 Vigilante motor into my 1977 Hornet X, and have run into a few problems, though, honestly, far fewer than I had expected.

I began test fitting the motor yesterday, and was pleasantly surprised at the compatibility of the parts, given how much I had heard about the nightmare these "oddball" swaps can be. The stock I6 engine mounts will work with little modification, and the flexplate mounting surface on the 327 happens to sit a very convenient 1/2in farther from the bellhousing mounting surface than it did on the I6, allowing space for a 1/2 inch steel adapter plate between the engine and trans.

The only unresolved issue I have is what to do about the starter. during the test fit, I discovered that the starter for the '77 trans falls exactly where the lowermost bolthole on the arm of the passenger side of the 327 does.

Here is my question: Does anyone have any better ideas what to do about the starter, before I take a sawzall to the side of my very pretty, and very old engine block?

Haha. Glad you approve. I can't figure out how to post photos straight to the site, so I hope this link works.

Apologies for the poor photo quality. I just got off work, and its dark.

I just held up the dust cover from the transmission to illustrate the problem. I guess I'm just concerned about removing what seems to me to be a key structural component of the mounting face. The original mounting point for the starter on the 327 seemed to hug the right head, and it sits too far away from the 258 flexplate, which is about 1.5-2 inches smaller in diameter than the 327 flywheel was. The 258 starter seems to be the only option.



Edited by jeepconvert - Apr/18/2017 at 11:50pm

I'm highly interested in how this one works out.

That's what I'd do too. I'm assuming you are making your own adapter plate? Just remember that the trans has to be pefrectly centered on the engine. That's why the alignment dowels for the bell -- bolt holes have too much play! IIRC the trans can only be off center by 0.002" -- any more will cause issues.

One more thing -- since you are using a 258 trans, it's probably a 904 (assuming 72 or newer). Get a towing/RV shift kit and add a trans fluid cooler. Then it will probably be okay for a cruiser. If you plan on running it real hard you need more transmission or have the 904 built to take more power. Many drag racers build the 904 up, so there are plenty parts to do it. The 904 is lighter and takes less power to operate than the much stronger (and heavier) 727. A 998 or 999 would be better, just harder to find in 2WD (AMC used the 998 behind 304s, 258s in Jeeps and Eagles -- but 4WD).

If you have the 327 BW auto you might be better off using it, assuming it's in good condition. A bit harder to find someone to rebuild, but all bolts in. Then you just need to mod the driveshaft and rear mount to fit. If it's a torque tube trans you can get a later model driveshaft yoke and either leave the TT flange alone or cut it off -- the seal is the same. The TT yoke is too short to move in and out as you drive though.

Is this one of those, "Just because I can" type of swaps or am I missing some sort of information that makes the 327 vigilante motor something special? Don't take it wrong I think it is cool to get a WTF is that reaction from people and this is certainly one of those cases. But pretty tough endeavor to say the least and on that front it would have frsutrated me to the point of changing everything over to a 360 or better. Very cool motor though.