Need to rebuild a Holley 750 double pumper.
Is it hard? I have taken apart many dirtbike and quads carbs off to clean but never have I done a big carb like this. Or should I just take it in? What would be the cost any idea?  Thanks

Not hard at all. 

Take pictures of the linkage to help make sure you get it back together correctly.

If its been setting for any time you should get a can of carb dip to soak the parts in (I like the Barrymans or McKay brands if you can find it).

Be sure to use the Holley style needle & seat assemblies.  The ones supplied by Hygrade or BorgWarner can be problems.

Good luck

Don't take it in

You can do it!

It's straight forward, take it apart, clean each piece, replace with what comes in your kit, put back together

When you buy your first carb kit you'll be like is this all there is to replace 

Its like changing the battery in a TV remote,  just remember witch way they go

ha, from a smart ass phone is more like it..

by the way   74RODGERS   kz650  as a kid  .....  you go mr.  my hat is off ..

BUY A GENUINE HOLLEY KIT....REPEAT....BUY A GENUINE HOLLEY KIT. Look at the numbers stamped on the side of the Power Valve ( 45-105 ) your kit will probably come w/85). Most common. Be careful when you put the outer bowl gaskets on...there is a hole for the accelerator pump...only on one side of the bottom of the gasket.  Other than that....really pretty simple. DON"T TURN IDLE PLATE SCREWS. Initial idle mixture ( as in all carbs) is 1-1/2 turn out from "lightly seated".

Lemmie know if yer cornfused.

GregS