Need some opinions (motor & trans)

[HatGuy]

Well it’s planning time for 2006. My 72’ K5 Blazer Highlander now has 147,000
Original miles. So it’s time for some decisions. First of the year I will have $5,000 to spend and I need some input.

1 Motor. After pulling the original and seting it aside for safe keeping
should I install? These are on Summit Racing's web site at : http://www.summitracing.com/
a. GM Complete 350 cid 330 HP Crate Engine NAL-12496968 $3,495.95
b. GM 350 cid 290 HP Crate Engine NAL-12499529 $1,818.9
c. GM 350 cid 260 HP Crate Engine NAL-10067353 $1,419.95
d. Rebuild the original 350 motor . Price ?

2 Trans. After pulling the original and seting it aside for safe keeping
should I install?
a. 700R4 Level 1 Part #:L1MP700R4 $895.00 http://www.bowtieoverdrives.com/cata...m.php?ITEMID=7
b. Rebuild original Turbo 350. Price ?

Rear end is 3.73:1 but not Positrack. Thinking about 32” tires.

One other option is just keep driving it Utill something breaks then fix it.
It smokes (on cold start up), leaks every thing (a little bit). It's my daily
driver but its only 5.5 miles each way to work.
Thanks in advance