Engine code

[STRUTYOURSTUFF]

Hey guys. First off thanks for all the great advice over the years. I just picked up a 1966 Fleetside yesterday. Trying to figure out the engine code. Haven't really dug into the truck yet. The code I got off the front engine plate is FII04WA. What I'm not understanding is the I's in the code. Thought these should be numbers representing the month. Any help would be appreciated. Jim W

[Rich 5150 69]

They may have used I`s as a replacement stamp in place of the number 1 due to wear..I have seen it before..these numbers and letters where installed in a jig and hand stamped into the blocks just prior to install into the frame. Also at this time GM was trying to help with vehicle theft with some ( changes ) stamping trans codes into the engine suffix codes II in some cases meant power glide in `65..if we are reading yours right it is the 11 month 04 being the fourth day..

[STRUTYOURSTUFF]

Thanks Rich. Kinda thought that was the case. The WA would be a 283, 307 or a 350 no?

[Rich 5150 69]

`64 to `67 283 C.I. you then refer to you date code casting on the block, it will be three digits. ( if you can make it out )

[STRUTYOURSTUFF]

Thanks Rich. I was told that this is not the original motor. Did 283 come with 4 barrels?

[Rich 5150 69]

Originally Posted by STRUTYOURSTUFF

Thanks Rich. I was told that this is not the original motor. Did 283 come with 4 barrels?

Not in the trucks, standard was the rochester 2 barrel, standard heads ( non power pack ) lower compression 8.5 to 1, this gave the more low end power and torque.