height of engine compartment

this is just a quick question. i was wondering what model of truck has a taller engine compartment? ive been thinking of the cummins in a chevy and my mind's been spinning. so does the older or newer (90's) style have a taller engine bay? thanks a lot guys.

the squarebodys have more room under the hood... i have seen a cummins in a 88-98 style truck and they had to extend the front end about 3 inches on the back side of the fenders(kinda hard to explian) i guess they didnt want to mess with the firewall so they just moved the front foward more.

^^^Like a long hood Peterbilt.

awsome thats all i needed to know