Well after some help awhile back I finaly got to the vin stamped on my block and it is correct with hidden vin on cowl for the 69 350 ho engine. Yeay for me. Tomorow the engine and trans will come out together and was tring to figure out how to detirmine if the trans is factory correct. It is a 4spd muncie, so my question is there a vin on the trans aswell? Where would it be located? PHS shows just 4spd for my car so I imagine it is a m-20 not a m-21 close ratio. Any help here would be apriciated. Ohh also where would the code be on the rear axel? And what code should be for a 69 350 ho 4spd with factory 355 saftey track? rear?

Sounds good!
Check out this auction to help you with where the VIN should be on the trans;

http://cgi.ebay.com/ebaymotors/1969...itemZ170082116052QQrdZ1QQsspagenameZWDVW

Passenger side, main case where the tail shaft meets main case. stamped below date code if looking at it from under.

You'll find the codes in the 1969 Firebird section. http://firstgenfirebird.org/firebird/1969/id_numbers.html

http://www.5speeds.com/muncie2.htm

M 20 close ratio is correct.
< http://thefirstgensite.com/library/diffs/differentials.htm >

M-21 was an option for V8 only. 3.90 and 4.33 rear.

I highly doubt the RPO afforded a 350 HO a 3.90/4.33 rear to allow a close ratio trans.

So I am 100% sure your Muncie is an M-20

Thanks for all the great info once again guys. Unfortunatly the weather turned bad again here over night and now my Brother can't make it down with the engine crane today. I will let ya know when I get things out to get a better look.

My Firebird parts catalogue indicates a 350 HO with a 3.55 rear gear had the standard ratio 4 speed. With a 3.90 rear, the 350HO had the close ratio 4 speed. All manual cars that received the 3.90 or 4.33 gears sets had the close ratio 4 speed according to my book.

Code for lock diff:3.55 is ZH, 3.90 is ZK, 4.33 is ZM. Y means Std diff, Z means lock diff, last letter is gear ratio.

Look here.,.

http://firstgenfirebird.org/firebird/1968/sales_manual/O-chart1.html

You could get a 3.90 with a 350 HO close ratio.

This is a 68 sales manual, but the engine output did not change but by 5 HP for 69. I'll try tracking down my 69 stuff.

From what I saw, it says what I said. The "Donate" sidebar blanks the FF code so I looked in the trans section and the close ratio trans comes with the special order 3.90 or 4.33 gears.

In my parts catalogue, the '68 chart doesn't split the ratio choice but the '69 chart does. Same as above.

???