Interchangeable parts

[Rob88]

I have a 77 Gremlin X. It has the factory 258 inline 6. I am wondering what other make of cars have interchangeable engine parts.

[Big Bad AMX]

I'm not sure I understand your question. Are there specific parts you're wanting to swap or ? It's just that the 258 has so many parts available for it I can't see any benefit of using parts from other auto manufacturers. AMC used them in their car line as well as their Jeep line. Chrysler continued to use it up to a year ago (somebody else will have to comment if Chrysler is still using them - or when they stopped).
There's a lot of aftermarket parts available for them. Look in Jeep catalogs to see what all is out there.

[Kem]

In my 258 that has a the rocker bosses machined for roller rockers{which do not fit from a 401} I used rocker pivots from an Oldsmobile 350 V8, and pushrods from a 292 Chevy six to compensate for the machining after I had to go back to stock stamped rockers...... But, that was just me....
The later 258 Motorcraft distributor will fit in place of your Presolite ignition used in 77. Presolite parts may be getting rare, but the Motorcraft parts are everywhere. Something to consider unless you want your 77 to stay correct. It is possible to use a HEI Chevy 250 inch 6 cylinder distributor in the 258 if the drive gear is changed. I have never tried this, but have heard it works, if you prefer a HEI over the Motorcraft.
Thermostats from a Chevy small block or Olds V8 will fit the AMC 6. Stant makes a 205 degree thermostat for these engines, just in case you live in a cold climate.
A Ford Motorcraft 302 carb will fit the AMC 258 2bbl intake if the Mr. Gasket #1937 adapter is used.

[Gremil]

I have done two six cylinder Gremlins with Clifford aluminum 4 barrel intake and twin headers. They run better than the stock V-8s acceleration wise and still get great mileage if you don't change the cam or differential ratio.

On my '77 Gremlin I switched the sloppy unreliable motorcraft distributor to a GM HEI and the performance difference was very noticeable. This engine already has the aluminum Clifford 4 barrel intake and 600 vacuum secondaries Holley and twin headers. My previous did used mechanically driven secondaries, but was a 4 speed manual transmission.

Here is a picture of my engine with details about how I did everything:
http://www.upmpg.com/projects/amc_gremlin/engine_drivetrain_025.htm

This engine runs really good and has better than expected power and accelleration. I used the vacuum secondary Holley this time around because of the automatic transmission. However, I am building a 258 for this car that will have a mild cam and performance cylinder head. I will replace this Holley for a mechanical secondary carb at that time (probably).

It isn't hard to do a distributor change on these engines. Here is an article on the how's and whys:
http://www.4x4wire.com/jeep/tech/electrical/hei02/

The GM HEI distributor is a one wire distributor and easy to wire in. I really found it easy to install. Just read this article first before doing it.

Doing a AMC six this way is damn fun! They sound incredible and run great. I have to open the hood a lot to prove it's a six. :D