i need help trying to figure out what the casting# on the lm1 350 255hp block might have been on the original motor in my 69 rs. the car was a sept. 68 build. i have alan colvins book(chevrolet by the #s)and he does not list a 255 hp 350 in his book.i am thinking maybe a 3932386 or 3932388. anybody have an early 350 rs that can tell me what they have? also was it a 2 bolt or 4 bolt motor? rb

rb is could be either the ...386 or ...388 block and could be either 2 or 4 bolt. The LM1's Ive seen in here over the years have been mixed. colvins is supposed to update their info. on next publication regarding the ...388 block as its nearly as popular as the ...386 contrary to previously published information. Old ebay ads used to shout "rare ..388 block" but they are as common as most all blocks that year. Go figure. Mine is Oct 68 built LM1 from Los Angeles. Is your car a Norwood or LA car?

jim it is a norwood car i was going to try to contact gary and ask him why he didn't list an lm1 motor. there is a 69 rs on ebay now with an original motor and he said it is a 388 block also.i am going to see if i can find the correct motor for the car but wasn't sure what i should be looking for. what is the block# on yours? 2 bolt or 4 bolt? the car#is 512000

mine is ...388 and 4 bolt LA car. remember too the LM1 was discontinued Jan 1 of 69 but the ...388 block could still have been used in other engine combos.