Will a whipple from 00' tahoe fit a 03 Denali?
 

Will a whipple kit that a was on a 2000 5.3 Tahoe fit my 2003 6.0 Yukon Denali? If so what will I need to make it fit. I wouldn't be using the whipple electronics.

I dont think its a problem... the main thing is the harness for the throttle body... since yours is DBW ...

I think the 03 has a return styl fuel system and the 2000 does not.. I am sue others can verify that.

didn't they got to a returnless system on 2004

Anything can be 'made' to fit.
It's a question of ease and how skilled you are at adapting things. That or how much you're willing to pay someone else to do it for you.

The early trucks had a return line and pressure regulator under the hood. I don't know the exact year that went to returnless, but my 2005 is returnless.

I recently installed a used kit for a 99-02 truck on to a friends 05. You will need larger injectors of coarse, 43lb are the easiest because they are plug and play. You will need get a crankshaft pulley off a 99-02 4.8,5.3, or 6.0l. The pulleys on the 03 and up will not match up to the whipple crankshaft pulley. I got one for like $20 at a local salvage yard. Lastly you will need the new style throttlebody elbow from whipple, the throttlebody will hit the firewall. I cut a recess for the throttlebody clearance on the firewall but do not recomend this, get the elbow from whipple. If you happen to have any questions PM me.

Later Jason

2004 Is when they switched to the Returnless fuel systems on the trucks....

I was trying to think what difference it makes if it's returnless or not. I just remembered the Whipple craptronics block off the return line under boost to 'up' the fuel pressure.
Shouldn't be an issue as long as you use bigger injectors.
Actually, you don't need to use the whipple electronics. Just tune the truck to suit. You may need to upgrade all of your injectors to a bigger size. This would be a better way of fueling and easier to tune.

04 is when they went to returnless system, the whip should fit only thing might be the dbw, like stated above..
JOHN