The older ones were not "rated" for +P ammo, but you could feed it a limited diet of them. I carried +p in mine years ago, and the model 60 I have says .38spl while my 642 says .38spl+p on the barrel.
If the barrel is not stamped +p I'd still carry +p in it but not feed it a steady diet which is what I do with my model 60, where the 642 is rated for it and I wouldn't have a problem putting 50 rounds through it.
The older ones were not "rated" for +P ammo, but you could feed it a limited diet of them. I carried +p in mine years ago, and the model 60 I have says .38spl while my 642 says .38spl+p on the barrel.
If the barrel is not stamped +p I'd still carry +p in it but not feed it a steady diet which is what I do with my model 60, where the 642 is rated for it and I wouldn't have a problem putting 50 rounds through it.
I like the model 36 and have owned a couple over the years (snubby & 3 incher). Only ran .38spl through both. I now own a 442 (minus internal lock) which is rated +p and load it with Hornady (best overall results).