Need advice - blown head gasket
So we tried to take the HornBus to the Longhorn's game in Nebraska. We made it from Austin to Wichita before we blew the head gasket - maybe more accurately, we had a leaking head gasket. Hornbus is still hanging out at a truck spa getting some work done. For background, here is what I know about the bus:
Engine - 7.3 international
Head gasket is leaking
Heads are cracked, but repairable.
Top speed - I've never wound it all the way out, but at about 55 mph it is running at about 3300 rpm.
Speedometer is broken, 55 registers as 75 ish.
Miles - who knows, but it is at least 200k.
Built - 1977
Transmission - 3 speed automatic. Wish it had overdrive!
Length - 3/4 length
Body - is in great shape. And, I have a ton invested in the paint job (way more than I paid for the bus)
Here are my questions:
1 - The head apparently can be repaired. Is this a good idea? The mechanic I'm working with seems very familiar with the engine and feels confident it will work. Otherwise he is recommending finding heads somewhere used.
2 - should I be considering an engine replacement? If so, what is a good replacement for the 7.3?
3 - I am looking at getting a new rear end with better gear ratios to improve highway speed. Anything to keep in mind?
4 - any other (reasonably priced) options to improve highway speed? We want to be able to take the bus on the highway for long trips.
5 - would there be a substantial benefit to replace the whole drivetrain - motor (turbo diesel, transmission, rear end)? What would something like that cost?
Anything else anyone can think of would be welcome.
Hook'em! And, I will post pictures once I get off my mobile.