Engine Dilema!

[86SILVERADO]

Well,

The 307 in my dump burns a quart of oil every 100 miles. I have a $2500 350 in my half ton. I still have the original 305 which runs fine. I also have a 350 stripped down from a 72 which ran fine lowest cylinder was 130 and highest was 155. I tore it apart though for no good reason. So now figure if I was to use that motor I might as well re-build it which I could do for around 1200. I have the money right now but am probably going to buy a plow and don't really want to spend big bucks on another motor right now. I guess a list of what I see are my options would be best.

1. Swap out 350 for 305 in 1/2 ton and put 350 in Dump.

Pros:
a.brand new 350 don't really need it in 1/2 ton.
b.saves me the most money

Cons:
a. Will take me the most time which as always is at a premium.
b 305 really should be re-built even though it runs fine and burns little oil it still has 150k and leaks oil from every possible seal etc.

2. Re-build 350 from 72

Pros:
a. I have the motor and it would otherwise probably go to waste.
b. Don't have to waste the time pulling the 350 from the half ton AND re-installing the 305.
c. will have a 350 in both trucks although I am kinda missing the 20 mpg from the half ton.

Cons:
a. more money than I really should spend right now and going into the slow time of year for me.


3. Run the 307

Pros:
a. No $$$
b. No time

Cons:

a. oil consumption especially because I am wanting to plow with it this winter.
b. I am about to lose the throw out bearing and I know I gotta do it soon and am thinking well If I have to drop the tranny why not pull the motor at the same time and you know how that goes..LOL

4. Crate 350

Pros:

a. same $$ as re-building the 350 but with warranty (which actually means less to me than KNOWING that I will not have to go and pull the motor again in a month)
b. no time spent re-building the 350

Cons:

a. potential probs with crate motor.
b. 350 and 305 probably go to waste or rather I get like 400 for the both of them which I am not sure is worth it to me either.

So that was a mouthful. The only other thing I can think of is some kind of oil stabilizer or additive for the 307 which I have never done and would have to have some pretty convincing evidence to bother with.

Any suggestions...LOL