Went and drove this old squatty dually, single cab. Cool looking truck but the transmission whined/whistled as it got to the top end of ranges but not into the 4th gear. It didn't shift hard or oddly, just a high pitch tone. Any ideas what it might be? Trying to decide a price on it but want to make sure I leave some room if I need to replace the transmission

I'd first check fluid levels.

On bright side, cheap and easy transmission to replace.

Exactly

454 and 4l80...hell to the yeah. Buy it and rule 1!

Well, she came home today. Seller took a lowball offer and now it concerns me. But it drove all the way home, we will figure the rest out. My 15yr daughter is excited about her first vehicle. It almost isn't fair.

That's awesome. What are those wheels?

OP gonna make me buy another GMT400

Yo, I have no idea but they will be last to go on the list of things.

She has named him Napolean.

Just help us with this one. That should scratch the itch.

I can donate a ECSB rear bench seat for being bolted down on the bed.

Regarding the transmission if it needs replacement, you could use just about any year of 4L80e. The LS 80e has a different bellhousing bolt pattern, but will still mount to SBC/BBC. If using a 97+ transmission, you must ensure that you use the proper transmission cooler fittings at the transmission. Slight difference on the case for mounting the NSS, I want to say that transmissions prior to 95 didn't have provisions for mounting it. Alternatively if you want to do a bench rebuild of current transmission, I know a guy in Sugarland area that's very good and great pricing. He rebuilt my 80e after I had some issues with the initial builder who was located in FL.