I have a 67 conv. (I think the date code on body tag is 05C) that the previous owner said had a 68 350 in it. I recently got the 67-69 restoration book and I think the motor may be a 326. The casting # is 9786339, heads are 140, date code is d287. The block is a YJ and there is a no. stamped close by that reads 595511. I didn't find a verticle no. near the timing chain cover. It had a 68 4-barrel intake on it #9794284. Is this the correct motor for my car (vin# 223677u142693).
Check the date code on the block, it is near the distributor on the block. It will be cast into the block with a series of numbers & a letter to indicate the date. For instance, a code of C138 would be March 13, 1968. If this code is at least 3 to 4 months before the actual build of the car I would say it is the original engine. On '68 & up it's easier to prove originality because part of the VIN # is stamped into the block. Your head casting # is a 2 BBL head. #141's were the 4 BBL casting. The head casting is a 326 engine head.
and for $35 they will provide the original invoice for the car which will tell you all the original equipment that was ordered. There is also an "engine unit" number listed on the invoice that you can match to the number to the left of the timing cover which will tell you if it's the original engine.
