Having trouble identifying my supposed 1500 1975

[barnstormerj]

I look up my sn off of the lower mount bracket, it has sn of a 1975 1500 . Now, when I look up the fuel pump, it has the looks of the 140 hp pump, so that is what I ordered. is there a sn on the engine block, and where would it be. It has thunderbolt ignition. My other question is, could this be a cobbled up mess, as I have no history of it, when I changed the timing belt, it had 1987 in black marker pen on the power head side. Can these engine parts, cowling, ect. be swapped around, even though it says 1500 on the cowl, actually be a different engine? kinda like a small block chevy, you can not tell till you sn it out? Thanks. Jack

 

[Laddies]

Re: Having trouble identifying my supposed 1500 1975

There is a boss cast into the block 1/3 of the way down the starboardside of the block with the serial number stamped in, just to the rear of the port cover.

 

[barnstormerj]

Re: Having trouble identifying my supposed 1500 1975

There is a boss cast into the block 1/3 of the way down the starboardside of the block with the serial number stamped in, just to the rear of the port cover.

Is this visable after taking cowling off? or do you need to pull the side covers off to see it?

 

[Laddies]

Re: Having trouble identifying my supposed 1500 1975

It's on the side of the waterjacket on 2 or 3 cyl, about 1" wide and 2 1/2" long should be 7 digits