[427TJ]

Wouldn't a C427X fit any Mark IV BBC with rectangular ports? If it's an LS7 then it's a 454. Sounds like a crate LS7 with a C427X intake. (However, I didn't check the pad code "XCH.") Sounds like a nice piece to have, especially if it's still standard bore and not damaged internally. 12.5 LS7 pistons and that 320 duration cam are a bit too much for 92 octane pump gas though. As far as keeping it, it's getting so that any old big-block (Mark IV short deck) is worth keeping. Another 10 years and guys will be throwing money down for 2-bolt oval-port engines. Look at what happened to small-blocks. Suddenly a 283 or 327 is something everyone wants, especially rat rodders. As this stuff gets old it becomes gold. (Rhyme not intended.)