Is there a web site where I can look up original part numbers for various parts on differnt models/years?

Not a website, but you can get a copy of VADIS, which has everything 1975-present.

Jim,
Thanks for the quick response.

My problem is that my car is a '75 242, which is making finding parts somewhat difficult. It has the chassis like the '76-'81 240's and a B20F engine which should be like some 140's and some 1800's but I'm not sure which parts interchange and which do not.

It would be nice to have an online resource so that I can compare parts from different years/models.

My current problem is that my thermo time switch is bad. I can't find a used one. I have found them new for the 140 and 1800 for as little as ~$30.00 but the only place that has the one for a '75 242 wants $140.00+. Will the one from the older cars work in mine? Is there a difference in the part number? Is there a differnce in the thread size between a B20E and B20F engine TTS hole?
Is there any electrical difference between the one in the older cars and mine?

I guess I'm just too cheap to spend the $140 Vs. $30 but to spend the $30 and not get the right part would be a pain.

I don't think there is that much difference between the thermal time switches.
What they do is time the extra rich mixture while cranking, making it longer
when it's colder. I'd bite the bullet and get the $30 one.
Or e-mail me offline and I can do a lot better.
--
George Downs, Bartlesville, Heart of the USA!

My only concern is the thread of the unit.

D-jet units are all imperial threads, and the later B20 is a metric block.

You might be better served getting a TTS from a B21 rather than a B20E/F with d-jet.

Jim

The Thermal Time Switch is a pipe thread which is pretty much universal.
And the late B20 Block that I have worked with is only metric on the bellhousing
mounting bolts and the maincap bolts, both of which are M12-1.75. All the other
threads on the block are Unified, not Imperial, just like the earlier B20s and
B18s, not to mention the B30s. Some of the sensor holes, particularly the temp
sensors seem to be UNF (formerly known as SAE) threads.
In any case I have them from both B20 and B21 so it will be easy enough to check
them out, which I plan to do in the morning. They sure look alike.
--
George Downs, Bartlesville, Heart of the USA!

My thinking on that was that a B20E and a B20 F are most likely going to have the same thread. (?)

George if you have a used one I can at least try, I think it would be worth a shot. I'll contact you.

Thanks again.