I don't know myself, but second the suggestion that you post this into the 'making a bed' forum.

Also, if the factory assembly manual is available you could get the data from that. Possibly the Restoration Pack from GM would tell you. There is an online forum that has lots of manuals in PDF format, which might be helpful too.

http://chevy.tocmp.com/index.htm

Here's a Master Part's catelog from '29-'54, which might have what you need:

http://chevy.tocmp.com/1929_54chevyparts/index.htm

Here's a link to a page of resources that might put you in the right direction.

http://chevy.tocmp.com/chevyresources.htm

'51 Chevy 1/2 ton w/'62 261, HEI, offy, fentons, dual carter/webbers, t-5 & 12 bolt posi