I have the GM 1983 Firebird Service Manual... and it's great for reassembling everything for my car, if I had the correct pieces... but where it falls short is that the previous owner had done work on it and used all kinds of various nuts and bolts and washers... some even are missing. The manual I have just shows the reassembly picture and identifies the parts as "Bolt" "Nut" "Washer" etc. Which would be fine if I had all the correct parts on hand. Is there a different source that lists "six M10 1.5 bolts for bellhousing" and "four 3/8" washers for bracket" etc? Main concern is transmission crossmember, and engine accessories bolts, nuts, washers, etc so I can get the drivetrain back into the car with the correct pieces.

Thanks.

Not going to find much like that. The Parts & Illustration Catalogs have some of the hardware listed. The only other resource is the Camaro Assembly Guides, which have been offered for 1982-1986. The title is a bit of a stretch. What the Assembly Guide really is, is a collection of engineering sheets with illustrations, part numbers, the occasional torque spec. The pages were something that was collected from assembly line documents, they're not exactly in a concrete order, there's no index or table of contents, and as I mentioned they're for the Camaro not the Firebird. So you're kinda in a tough spot. Best bet is to ask here when you get in a pinch and need to know.

PS: Nearly all of the above resources are going to list a part number for a piece of hardware, rarely will they tell you the actual size. What you run into with 30 year old part numbers is that they've all changed. They've been updated, discontinued, etc to the point that it's often difficult to find a piece of hardware even if you have the number. When you do, sometimes the current version of that nut or bolt is pretty far from what it was 30+ years ago.

Thanks for the reply, That's what I was afraid of. Well, really right now I would like to know the proper length of the 4 bolts and size washers that attach the crossmember to the body for a T5 and the 2 bolts that hold the mount to the crossmember. If someone knows that info, or could measure theirs and maybe take a pic of one, that would be extremely helpful. The others I know I'll need are for the accessories that I'll get to in a couple weeks.

I think those bolts you want are M10x1.5x25, should fit for all 6 locations

Great, thank you! Any Idea on the washers? Like I said, it's got 4 different ones. I'm not OCD, but it's getting me there.

The 4 original washers for the crossmember are very very thick octagonal shape. You won't find them new, so you'll have to source another M10 washer, or get them from someone used, which shouldn't be difficult. not sure on the mount washers, but any washer that fits the screw and the space should be fine, just like a close head washer.

That helps a lot! Thank you.