it would actually be better for you if you go with the L26 upper. The opening is 75mm

I am amazed that Bill mentioned a proper signature has no plugs or wires. It'* awesome, but I haven't thought about it yet. Nice work.

On the L67 TB, do you have all the proper info on what to block off with JB weld? There are some things to change when you put an L67 TB on an L36 UIM. It would cost less than $10 in epoxy putty. Also with such a seal, you could port your L36 UIIM to 75mm or even larger if you really want to. No need to go aluminum if you aren't worried about cracks. Those cracks don't happen early anyway.

Why try to port thin wall plastic, when there was an L26 upper in the JY by him?

Good point. I'm just trying not to be an L26 UIM evangelist.

how about a LT1 Maf could I use that?

The LQ4 is a truck MAF sensor from an engine of the same displacement. The thing is, you basically need the standard GM wire set for a MAF sensor, and then you can solder the wires to your own 3800/LS1/whatever style connector you want.

I found an LS1tech.com thread on something kind of like what you want to do. Some guy took the LQ4 MAF sensor and wanted it to work with his LT1. So there'* a pinout on how to get the LQ4 sensor to work on an LT1. Then you have to follow that to see the LT1 pinout and make it work on your 3800 sensor. A bit of a stretch unless you read it and get it right away. I know things I write can be confusing sometimes, so let me know if I need to clarify something. And in case just reading the thread from the link helps, here you go:
http://www.ls1tech.com/forums/pcm-di...pter-help.html

looks easy to adapt so can I put it in line from my air box to the TB.

Sure, you can use an external MAF even with no throttle body if you're up for it. Please use a throttle body though.

You're an odd man rad. So if I pick this LT1 MAF and block off the maf hole on my TB then tune I'm good.

Yes..

You'll want to program in the new maf table before putting it on..and do it. Most guys find the LQ4 (of the same displacement are you nuts Rad) from a 5.3/6.0 truck, vette etc to work great, and they are cheap on ebay. An LS1 will also work. Shouldn't be any reason why you can't be that little bit different.