That engine won't be a direct drop in. You'll probably have to fabricate a motor mount, or at the very least drill some extra holes in your chassis. I don't know if your clutch and bell will fit on it, or if it will line up with the spur if it does.

Honestly that's probably way too much engine for that truck. You can get all the power you'll ever need, and then some with an .18 CV-R. and it should drop right in.

That sh.28 in a stadium truck will likely not be any faster or quicker than an .18CV-R The extra power it produces will only make it harder to control, and easier to lose rear traction, so you won't be able to acclerate any faster. The CV-R has a higher max RPM so it will likely be faster than the SH for a given gearing.

Now, all that being said. If you're doing it for the challenge of shoe-horning a big mill into a little truck, and to learn and experiment, then go for it and good luck. Sounds like a fun project, and you'll have some bragging rights, because it's doubtful that there's many ST's around with a .28.