1970 cst/10

[chill]

i just bought a 1970 cst/10 2wheel drive pick up and haveing trouble with finding any information on engine # in it. It is CF168148 ON FRONT RIGHT BLOCK also it is 6 lug wheels it has a 454 turbo 400 trans orig owner told me that when he bought it the 400 wouldnt tow his fth wheel very well so he took it back to the dealer several times when it was new and they finally installed the 454 need to know if that story checks out with the block ## cant find in any book looks to be a four bolt main by the holes behind oil filter THANKS ANY INFORMATION ON THIS PICK UP BEFORE I RESTORE IT WOULD BE HELPFUL