Should I mod/rod my truck or not?

[shifty]

My biggest dilemma:
So, I just bought my '68 swb shortbed step.

Truck is in great shape but engine needs an overhaul. The truck is has 98% of the original equipment in it, including the original I-6 engine and tranny.

I'm having a tough time deciding if I should work towards making everything 100% stock or if I should rod it out.

What do you guys think?

Should I bother rebuilding the original engine or just drop a new crate engine and MT tranny with floor shifter into it? (Might need to put in larger floor hump, I know)

Can I safely lower and bag my truck out with notching the frame or doing any seriously permanent damage?

Would rodding the truck out increase the value or decrease the value?

I've posted pics of the truck several times here already, but ... http://shifty.org/pics/68chevy/ ... just in case anyone wants to know what I'm dealing with.

I really want to smooth the firewall, drop a new V8 engine and manual tranny into it, lower it, bag it out, roll some 18" or larger stock on it and tinker with the gears. I also want to smooth out the firewall, shave some things on the body, add power locks and windows, remove the bench seat and add buckets, rework the sound system, add more gauges, add PB, PS and tilt steering, add A/C and .... hehe, I've got a long list.