MG Sports Cars

Found lots of info on this forum as to number identifications fo these emgines but I wonder if owners with these engines can also provide visual indicateors as to years, versions, olds/buick or rover configurations??...my engine is supposed to be 68 rover but looks like a buick? like as much info as anyone can provide....thnx

Your engine may have a mix of Buick, Rover, and even Olds parts. From pics you've posted previously, your stamped steel valve covers are certainly from a Buick. They wouldn't mount of Olds cylinder heads, so the heads are either Buick or Rover. (Have you taken off a valve cover to check for casting marks on the heads?)

One way to tell a GM block from a Rover block is the surface finish on the outside. Rover blocks were sandcast, whereas GM blocks were made on permanent molds (like a transmission case), so GM blocks have a smoother, shinier exterior surface finish.

Another way to tell them apart is to look for a pattern of small parallel ribs above the bellhousing flange at the back of the engine, just rearward of the valley pan.

You'll find the ribs on the Buick or Olds blocks, as shown here:

(note: this is actually an Olds engine. you can tell because it has six head bolts per cylinder and doesn't have dished pistons. Buick and older Rovers had five bolts per cylinder.)

As shown here, the little ribs are missing from the Rover version of the engine block:

Thnx.....great advice, will be able to piece it all together now between your visual marks and the casting numbers.