are normal gm blocks different than a marine?
my casting # is 8999289
on a website i found 3999289 its possible i mixed up the 3 with an 8 and it says its a 72-78 truck block. thanks in advance!
I was told there 454's that are dyno'd at 500hp from a marine shop in sacramento. they have holley 830cfm hp marine carbs, merlin high rise intake and looks like gil exhaust. i paid very little for them. I tried uploading pictures of them but cant for some reason???

Registered members can not post pics. There is no difference in the blocks. GM didn't make a marine specific big block.
Eddie

from what i can tell an 8999289 is actually an LS-6 block, is there any block experts out there?

Have You Tried Just Putting Your Casting Number Into Google? I Know Sounds Funny But Did Alot Of Research On My Bow Tie Blocks By Searching Google,i Am Almost 100 % Sure That The First Number Is A 3 Not A 8 Read On A Forum That Was A Pretty Common Miss Read

has to be 3999???

http://www.leverfamilysite.com/image...tification.pdf

zeke,
I am pretty sure it is a 3999289 I could not find a 8999289 anywhere in my books or engine builders software.

Anyway, it is just a generic 454 block that was used from 1970 through 1990 by GM There should be a date code on it near the casting number that would get you close to the year. If the block was not decked when the engines were built, you may be able to still see the actual engine serial number. If so, this site has a good list of them telling you what the block came out of originally.
http://www.nastyz28.com/chevy-engine-code-stampings.php

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

i googled 8999289 and it comes up as an ls-6 crate engine. the 3999289 comes up as a 2 bolt, i coulndt see anyone building a 500hp 454 out of a 2 bolt.
I bought the twin motor to this for a grand, complete with exhause bellhousing coupler and all
When i get some time ill take it apart and see whats inside these things.

I hav the same engine and it is stamped as a HI PER PASS whch means it is a high performance passenger. I can not find out what this engine is. Thanks, for any help, Dan

its probably a 399 mines the same mine is a 4 bolt main though

Take a look here http://web.archive.org/web/200805160...om/castnum.htm

3999289....454.......71-79...2 or 4 bolt, some "CE" replacement blocks had four bolt main caps