Valve seals and transmission slip

[chevymotocross]

Got an 87 Silverado 2wd with a 305. The truck has almost 200,000 miles on it and is due for some work. It's been lacking power and having some transmission slippage. When I bought the truck, it always smoked on startup. I am now ready to actually fix this once and for all with valve seals.

I was told to buy the umbrella type seals since the factory o-ring type stink. What is needed for this job and are there any suggestions to keep parts from falling into the engine when I do this job?

I will also be replacing the plugs after I do the seals. I never changed the plugs since I bought the truck 2 years ago, and who knows when they were changed before me. Plus with leaky valve seals, I bet they are shot. AC Delco recommended?

When it gets cold, like it is now in New England, I notice the truck has some wierd shifting when I first start driving. It did this last fall/winter as well. It slips a bit. Once the truck warms up, it shifts better. Fluid is at proper level. Should I change filter or is this transmission considered junk?

[old Rusty C10]

why not have the heads done over and do it 100% right?
if your tranny fluid is cherry red and doesnt smell all burnt id drop the fluid and filter and change it.. . You dont specify what kid of trans you have but i have a th350 in mine and frankly when its cold out i have this problem with virtually every truck i own when its really cold... one of my trucks is under warranty and i was told by the dealer its normal... i wouldnt worry about the shift issue but id let the truck warm up some before driving after it cools down

[chevymotocross]

Originally Posted by old Rusty C10

why not have the heads done over and do it 100% right?
if your tranny fluid is cherry red and doesnt smell all burnt id drop the fluid and filter and change it.. . You dont specify what kid of trans you have but i have a th350 in mine and frankly when its cold out i have this problem with virtually every truck i own when its really cold... one of my trucks is under warranty and i was told by the dealer its normal... i wouldnt worry about the shift issue but id let the truck warm up some before driving after it cools down

It's a 700r4 which I believe has been overhauled in the past. Fluid is red, not burnt, and at proper level.

I would like to have the heads done... but it's a wimpy 305 with 200,000 miles. Eventually, I will pull the engine and drop a 350 in it's place. For now, I just want to fix the smoke issue.