I bought an 89 full size blazer last year know it had a gasket issue. I had the heads replaced and serviced. Its still smoking on start up and doesnt seem to go away. The shop said it will after a while but it has a 700r4 missing 3rd & 4th gear so until i rebuild it which wont be for a couple weeks cant drive to see if it goes away. Will it just go away? and should i rebuild the 700r4 or swap for a 350 or 400 trans? Blazer stays.... Wife may go...

 

What color is the smoke first? Blue is oil, white is coolant, black is fuel. It could be a bit of oil or coolant that leaked down on top of the pistons during the head job. A good shop would have cleaned that up and any little bit left would have already burnt off while they checked it before giving it back. A bit of blue smoke on crank up is common on chevy v8s with some miles on them. That's the valve seals in the head. Its however NOT common on something that's just had a head job. Personally I'd be shopping for a new shop, sounds to me like a hose job and excuses for crappy work.

If you gonna drive the blazer keep the 700r4 with overdrive. If its something that's gonna be an offroad rig go with what trans (350/700) makes you happy. A th400 is way overkill both weight and strength wise for a factory 350. If you plan on heavily hopping the motor up and beating on it then a th400 might be a good choice.

700r4s get a bad rep but for 5 years I drove a 383 tubbed s10 on nos doing low 8s high 7s in the 1/8th with one. If you find somebody that knows how to build them and the tv cable is set right they are as strong as a th350 and have an extra gear. The guy I sold my truck to blew up the ford 9 rear but 3 years he's had it the trans is still going.

 

Its between blue and white. I havent been able to let it run much due to time. It sat for a long time before i bought it, and has been sitting since head work. It is killing me to see it sit with no play. The shop has gotten high reviews but i haven't had a good shop in years.

 

Sitting for awhile might change things then. The rings might be froze and need some time running to break loose. They also might not and you need a ring job. Most of the time if its the rings it will smoke all the time. Might be just some spill that got left on top of the pistons. Kinda iffy they didn't clean that but if they come with good marks for your area they might be the best option ya got. I know when I do a head job I break out a vacuum and rags to clean that up so the customer doesn't deal with that. Even if it'll burn off I don't want a truck leaving my shop that shouldn't be smoking doing it.

You can always crank it up, rev it up as driving it (slow, don't act like a 16 y/o ricer at a stop light) to get the engine running while sitting in park. I know its a shot in the foot on a new to you truck you want to drive but until you get a trans its all I can think of.

 

LOL (16 yo) any info i can get is great thank you. I will give it a try tonight. I have loved blazers since the first one i owned. Had to get rid of it due to rusting, but that thing was a tank. I will get this one right if i have to rebuild or swap the motor. She is going to the trans shop soon...

 

I hear ya, have always loved the square body suvs. Funny cause I don't like the trucks of the same style. I also love the first gen k5s but those I also like the trucks. Hell I'd trade my 69 gmc with factory v8 and ac for a base model 69 jimmy.

 

very true. I love the 70's model with the entire removable top. every one of those i find is in horrible shape or way over priced. I'm still pissed with my self for selling my 64 chevy step side.

 

As stated above, minimal idle time will rid the tops of the pistons of any oil that may be left on top of the pistons after the workt that was done. I would seriously get used to starting it everyday. The more time that goes by, the more time a shop has to validate that they are not at fault. I would start it everyday, idle it, bring it up in RPMs for a couple seconds and then idle it again, repeating it for a good 5 to 10 minutes or more. If everyday its smoking on startup then you have a problem and you need to get it back to the shop. If they replaced the heads you shouldnt have problems with any seals, valves, gaskets, ect. Take it back take it back take it back