does it run yet?
I was going to say my dad ordered a brand new GMC in 82 with a three on the tree.Looks good , 83 still had three on the tree.
A manual transmission?The 1987 R10 came standard with a column shifted three speed.
Martin
To be honest, I hadn't really thought much about how the crossmember might come into play. I haven't had a truck with a factory trans crossmember in a long time. It's going to be interesting. I need some pipe to hold up there to see for sure how it's going to line up. I might have to put a little dog leg in the pipes coming off the collectors. It's going to be close either way. I was thinking I might also be able to get away with making the pipe a little more oval shaped.Does that drop out at the bottom where you expected for a 2WD crossmember?
Can you just put some welding gloves on and bend those hard lines back closer tucked into the frame more? That would be fast and easy if done right. You might want to wrap some heat insulator around them when done in that area.
How thick are the flanges on those stainless bad boys? They look plenty thick?
A manual transmission?

The box with Hooker collectors showed up with everything but the collectors. It was apparent the original tape didn't stick and UPS re-taped the box, but obviously not before my collectors fell out. They are sending me a new set, but I won't get them until Wednesday. I wanted to get a plan for the exhaust so I bought some $26 collectors from O'Reilly and the only thing they had with 2-1/2" input was 2-1/4" output. Had to use the adapters to get 2-1/2" past the crossmember.Does your collector adaptor neck down smaller than the collector and then back up again suddenly? 2.5 down to 2.25 back up to 2.5 again? I think I would avoid that if possible. Even if it means cutting the flange off and welding it on to your pipe directly.
Haha! That's exactly what I was doing 30 minutes ago on my "get away from the desk" break. Honestly I think it's kinda fun to come up with exhaust routing solutions like that.If it only barely touches the crossmember, you could probably put a cut in the pipe from the top, but not all the way through, then bend it so the cut is touching again, and weld it shut. It may angle the pipe just enough to clear the crossmember but won't crush the pipe any, and the angle will be so slight it shouldn't hurt performance.
