Chris Craft/OMC model number cross reference

I’m having trouble sourcing parts, thanks in advance for any help. I have a 1975 Chris Craft 17’ Lancer. On the engine valve cover it says Chris Craft Model 307B101, which I believe is 215HP. Googling that for parts has returned very little. It is an OMC sterndrive and I’m assuming a Chevy 307. Did Chris Craft re-brand an OMC stern drive package? Is there an OMC model I should be using to source parts, something like TUFM-19EX-20D or TUFR-19EX-20D? I have found both in an old OMC parts catalog the previous owner gave me.

The OMC owner’s manual that came with the boat states the spark plugs should be AC-CR43K or Champion J6. A separate document that came with the boat and names the engine model number states AC MR43T. These plugs have a different reach, tip, and seat. I can’t validate which document is correct. In the OMC parts catalog, for the OMC models above, it calls out all 3 as valid spark plugs. Only the AC CR43k and J6 are for a 215 EX model only and the AC R43T is for 215 20D models only. Any ideas or are there additional markings on the boat that would help? I don’t know what the EX or 20D are.

Also, I have a small oil leak, which I’m having trouble finding parts. Can I source Chevy 307 intake and valve cover gaskets?

Thanks,

 

Welcome to the forum.

The first thing to do is ID the block, by it's ID number, which is found, usually under an alternator bracket on the front, left side of the engine, by the head. There are also casting numbers that will tell you what it is. It's possible it's a 307, but more likely a 305.

 

Thanks

Thank you PAR, I will try to look at that location the next time I can get to the boat. Still in storage.