On the new body style 07 trucks GM has changed the style of the water neck on the water pumps. The top neck is slanted now so it will clear big TB's on car type intakes like the LS6 & etc. in truck applications. I put one on my LS7 427 I'm building and the big 90MM Nick Williams TB clears it. Below are some pics. The 3rd pic is of an old style pump for comparision:

 

still might have to go to thr fbody accessories..another problem i faced i the belt would come right across the middle of the throttle body if using the truck accessories..unless you use the speartech bracket and pulley

 

Motor looks great. What were your 1/4 mile times on your 408 set up. That 427 will feel nice in a single cab.

 

I was planning on making my own bracket to drop the belt down. From looking at pics it looks fairly simple.

 

I never got a chance to run the 408 in good air. In high heat it runs deep in the 11's @ 119-120 mph. In good air I felt like low 11's might have been possible especially with the transbrake I have now. 60' times were terrible from spinning...1.8x

 

i did come machining on my lathe ande belt slipped off..i think the fbody accessories would look better on that pretty motor instead of havin a alternator stick out like a sore thump..thats just me..good luck and motor looks damn good

 

FYI, this water pump still does NOT fit with DBW 90mm TB's!!! It hits the TPS/electric motor cover on DBW, at least on the vette TB's. I've worked a bit with DR X to see if we can get his harness adapter to work with the TBSS 90mm TB (different internal resistance than the vette/GTO/ETC) for some more clearance before I go another direction and modify the water pump.

 

Yeah, good thing to note when you are swapping an 07 (classic version has the new pump too) into a pre 07 truck, you should probably get a new upper hose so it doesn't pinch down as it bends into that top port(like mine does for the moment).

 

Do you have a part number for that water pump? It might be just what I need.

 

The part number is 12600767 and normal selling price is $154