Found answer to question... need to know how to delete discussion after posting ..

It would be more helpful to leave questions and answers here so others can benefit from the research. If you had a question I'm sure others in the future will have that same question.

ok.. The tip of my hex bit broke off in the head of one of the tower bolts inside the housing.. I cannot get it out and have damaged the bolt head further trying to get that tip to come out.. It is probable that I will damage/destroy the cam tower to get that bolt to come out..

so.. my question was about interchangability of cam towers.. what I found was that according to the parts "katalog" for 82-85 and 85-88, the same part number was used for all models of the 2.5 sohc - 944.105.250.07. However, there still seems to remain a little mystery because the casting on my cam tower is 944.105.250.6R.

Thanks for putting it back up.

Get a long punch that is very sharp and punch a starter hole in the center of your broken tool. Get the best long drill bits you can buy and start drilling. Once the head pops off the bolt just pull the cam cover and use vice grips, PB Blaster, heat if needed to get the remaining stud out of the head. I have had to do this a few times when previous mechanics used SAE tools on the Metric bolts ;(

Those cam housing bolts can be really tight sometimes, which is a crime because they're only supposed to get 15 ft/lbs! Check all 15 wavy washers before you reinstall them.
Cam housings are cheap. I can ship you one. Don't mess up your head.
Don't confuse the casting number and the part number. If you see a 5R or 6R, 9R after the number, it's the casting number. That number is a good, quick way to tell early from late parts, but not good for ordering parts.
Good luck!