[oletrucks] BIG GMC engine question 426? or 503?

[jrdorsey <jrdorsey@strato.net>]

I'm hoping someone out there is familiar with big GMCs.

Is there any easy way to tell if an engine is a 426 or a 503, or are
they the same externally?

I'm going to have to clean it to read the casting #s, but that project
is down farther on the list. 

Thanks for any advice!
-- 
John
"49-50-54-57-79-95" Chevy 3800 Panel
'52 GMC 640 FMC Firetruck
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959