Truck blocks have a deck height (crank centerline to block deck) of 10.2" versus passenger blocks at 9.8". While you can get a longer rod in there, they tend to be a pain since you have to have the correct (read: more expensive) intake and distributor, possible header fitment issues and maybe even hood clearance problems. If you're not trying to squeeze one into a care, they make good race engines, though, and they're relatively plentiful. I'm sure he'd have problems fitting one under the stock hood of a 'vette.
By the way, light trucks - up to and including 1-tons - have passenger type blocks in them. You find the truck blocks in busses and heavy haulers.

 

Raised deck blocks are definitely a good performance idea. Chrysler took the relatively plebian 361, 383 and raised the deck height to create the truly monstrous 413, 426Wedge, and finally 440. The problem with the Chevy version is that I am doubting real seriously a single performance intake exists for the 427 truck motor so you're now putting some "spacer" in there and hence a really big airflow kink to run a mainstream BBC intake. Plus all the other problems listed above - custom sized headers, shock tower clearance, etc...I think Ive read that the 427 can accept a bore as big as 4.5" since these blocks were made for REAL trucks - not just some dually Saturday Night Special. For raace cars - I might consider one to play around with. For a street machione - forget it and just go buy a 454 out of some junker Suburban somewhere.

 

More like an/1/8th overbore, but with some dedicated grinding, I read something like a 4.60" or maybe a 4.625" crank can be made to fit for like a 550+ motor.

pdq67

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I think my friend may have been confused between light trucks and medium and heavy duty trucks. I had forgot about the heavier truck blocks. Thanks for the input.

 

Also, these bigger truck blocks are 427 or 366.....not 454's.