Shops, Barns, Varmints, and Trucks - Decode a 454 BBC,,,???

Print Page | Close Window

Decode a 454 BBC,,,???

Printed From: Unofficial Allis
Category: Other Topics
Forum Name: Shops, Barns, Varmints, and Trucks
Forum Description: anything you want to talk about except politics
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=192947
Printed Date: 22 Aug 2025 at 3:17am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: Decode a 454 BBC,,,???

Posted By: desertjoe
Subject: Decode a 454 BBC,,,???
Date Posted: 16 Jan 2023 at 7:50pm

I lucked onto a 454 BBC suppossedly to be in good condition. It came out of a mid to late 80's International Bluebird Bus with only 44,500 gentle miles,,,, Wink

Does anyone know how to decode the engine numbers? The set of numders stamped on a small pad on the front of the right side cylinder head are 109181 and numbers cast on the bellhousing flange is 10237226. Anyone got a clue? The computor is stamped for a 7.4 litre which is a 454. How does one know if it is a tall deck or regular? It has a HUGE auto transmission that is almost square,,,any value on the trans?? The fan and water pump arre also HUGE. This whole monstrocity was running and both exhaust manifolds look real clean and grayish and dry with,No sign of oil burrning,,,,

Any help appreciated,,,, Clap

Replies:

Posted By: Michael V (NM)
Date Posted: 16 Jan 2023 at 9:35pm

seeing how it was in a big bus ,,, I would make a WAG that the trans is an Allison, built for trucks,,, so that may be a tall deck engine...

Posted By: DMiller
Date Posted: 17 Jan 2023 at 6:16am

Spoke to local bus mechanic, likely not a 454 but either 366 or 427 tall deck could even be a 496. Processors in the big blocks can be coded 454 but really means nothing. Is just at 1/2” height difference between the blocks yet intakes or distributors will not interchange between them.

Posted By: Michael V (NM)
Date Posted: 17 Jan 2023 at 10:37am

I had a "chevy" buddy that tole me that there is hot rod stuff for the "tall" blocks,, jus gotta make sure ya tell them places like Summit or Jegs that is what ya workin on

they gots that extra so they have a 4 ring piston instead of a 3 ring piston,,, or so I was told

Posted By: DrAllis
Date Posted: 17 Jan 2023 at 10:44am

I'm no Chevy guy, but "truck engines" (not pickups) had the taller block just so they could use a 4-ring piston. Never was a 454 "truck" engine that I am aware of. 366 and 427's. Steel crankshafts, forged pistons, sodium filled/stellite faced exhaust valves, and a double roller chain drives the camshaft on a Ford.

Posted By: desertjoe
Date Posted: 18 Jan 2023 at 12:17am

DrAllis wrote:

I'm no Chevy guy, but "truck engines" (not pickups) had the taller block just so they could use a 4-ring piston. Never was a 454 "truck" engine that I am aware of. 366 and 427's. Steel crankshafts, forged pistons, sodium filled/stellite faced exhaust valves, and a double roller chain drives the camshaft on a Ford.

Well, this is some good news Re: the steel crankshaft and the valves,,,soon as I get the 14 miles of wiring looms off the engine where I can see the spark plugs, I'm gonna run a compression check to see if I have to open it up. My plans are to replace the throttle body and distributor with an aluminum mainifold (for Weight and apperance) and a distributor that will fire the engine WITHOUT a computor.

The Lady I got the engine from was helping me got the numbers off engine but she missed a few,,,,LOL. Number on pad in front of right cyl head is 10918FYN and number on bellhousing flange is 10237788. Wonder if it is a 4 bolt block? I would rather it be a 427 as THAT was always that Magical Hi PO number,,,,,

Posted By: DMiller
Date Posted: 18 Jan 2023 at 9:34am

A GM dealer Parts Department should be able to ID by Engine number.