will a booster form a 99 dodge 3500 be easy to fit with just a fabed up spacer plate or is there more to it.....besides all the hose work.......

 

If you use the stock Dodge bracket you will need to punch two new holes into the fire wall. The linkage rod is very close to the length of the stock vac booster rod.

Your biggest issue is the stock air horn going into the engine. The hydroboost setup will not clear it. A 2nd gen air horn might clear the hydro boost setup. I am not sure yet on that. I haven't gotten around to doing my hydro boost swap yet.

TWorline that makes the cooltubz can mod his tubz to clear the hydro boost. I had him mod a set to clear if the 2nd gen air horn doesn't.

The stock Dodge hydro boost from a 2002 model is 18.25" from firewall to the end of the master cylinder.

 

Here's a thread I started on hydroboost setups. There's some pictures of what I did plus some others.
https://www.dieseltruckresource.com/...d.php?t=169715