Not much to go on but here is what I know.

BBC about 2000-2002 came with a Bravo drive that had a stamp in it 136/16414 and has Stainless Steel gimbal ring. I will know more about the drive Mon/Tues. I believe it's a 1.36 ratio from this?

No Merc S/N plate, Numbers on top of block look to be machined off, Casting # behind flywheel is IV H4452 HIPERF. Carb replaced with a Holley so no clues there.
Stickers on flywheel cover indicate Bravo HP, I assume that is the coupler.

Pics that I have now are here:
http://phoenix.craigslist.org/nph/bpo/5107629626.html

Thanks for your time and thoughts.

Holy toledo ! Did you already buy it ? Looks like a smorgasgord of all kinds of stuff. Maybe even painted truck valve covers . Go straight for the 7.4 or 8.2 cast into side of block and gen 6 front cast timing cover. And then casting under valve cover. And please do tell . Could be a stolen hp500 disguised as something else...

Defiantly NOT stolen, Are you saying that there is either 7.4 or 8.2 actually cast on block? If so where?
How could I tell if it was a hp500?
Also looking at the heads they seem to be either new or just freshened.
thank you.

Look on the back of the block just above where the bell housing bolts on to on the port side of the block there will be casting numbers there hopefully those are not the ones that were ground off

UPDATE
Casting on side of block 74 so 454, dad nab it!
Casting# on rear of block 14015445
also on back of block is:
H 445
2 HP
M IV 2 HI PERF
Has gold rockers and Girdles
Any more ideas what this is.
Merc S/N plate missing from above starter
Will get head casting #'s Mon/Tuesday.
Thanks again.

Need head # looks like gen 5 or 6 valve covers timing cover specific to gen 6 those manifolds generally not found on either with a 7.4 on side .or a silver intake. If you got a good bravo with a good hp gimbal dont get all doom and gloom yet . Do tbe ring gear style calculate (or infamous merc outboard lower) cut through the voodo of your bravo ratio i.d.

the block is a 454 made between 78 and 90.it could be 2 bolt or 4 bolt main cap block.

Here is what I use for block & head casting numbers. www.mortec.com

http://www.mortec.com/bbc.htm

and a little more info for whomever

http://www.mortec.com/locatpg2.htm

Thanks for all the good info, very helpful.
Here is where I am getting confused, the flywheel is CASTING# 14096805 N which relates to PART# 14096987. Everything I found says for GEN V or VI for externally balanced forged steel crank.
This engine is MK IV, what could I be missing?
I guess my real question is, Does this mean that it has a forged crank? Or could this flywheel still be used on MK IV with Cast crank and internals?
Thanks again.