Newer GM 350 crrate

[Duffyjr]

I have 89 GMC that I put a used 350 crate motor in it. My mechanic pulled it out of his kids 93 Chevy truck when he wrecked it and said its only a couple years old with around 12,000 on it.

My question is, is this a better motor than the one that came out in 1989 as far as how its built, tolerances, materials used that sort of thing.

It also had a new/rebuilt transmission put in right before I got it and has about 2,000 miles on it now. At first if shifted hard but has smoothed out a lot. The thing is it shifts into over drive around 37 mph which I searched and found out this is normal for this setup. Lately when driving around town I decided to run it in drive in stead of over drive but it goes back to shifting hard, especially when it downshifts. Just not sure why it would do this, why would if shift different from being in overdrive vs drive? Do you think it will eventually smooth out? Sorry I'm not sure what transmission is in it but it shifts off a TV cable hooked up to the throttle body, I think its a 700 something.

 

[BubbaFL]

Depends what crate motor it is - GM Performance still makes old-school two bolt, two piece rear main, flat tappet crate motors, as well as better ones like the 350 Vortec crate motor.

Impossible to tell whether it was an upgrade, downgrade, or just a replacement without knowing what was in there originally and seeing what was done as part of the job.

 

[supton]

Can't say on the engine. I'd assume about as good as it was back in those days; and to use what was good back in those days as far as oil.

Sounds like the TV cable may be off. Leaving in drive around town sounds good to me, heck I do that on a much newer transmission. Since it's a rebuild it may be wortwhile to drop the pan and check the fluid / change the fluid.

 

[bubbatime]

Transmission drop down cable might need adjusted or maybe it has a shift kit installed in which case you will always have firm shifts. Could take it to a transmission shop if it really bothers you or just live with it.

As far as the engine, if it has power, doesn't smoke, and runs good, who cares. If it has flat tappet camshaft, you might want to run a heavy duty engine oil such as Rotella 10W30.

 

[bullwinkle]

Have to be careful, it is possible to damage the 700R4 if it's not adjusted correctly-
http://www.cpttransmission.com/tech_tvcable.htm

 

[Chris142]

I have seen many late 80's to mid 90's Chevy's go huge miles on the original engine. 400k+

 

[DoubleWasp]

We havended gotten some serious trash from GM years back. Seems to have cleared up a lot over the past several years.

Doubt it's a Vortec. Your intake would never have bolted up.

Should be an 87-95 engine, and very likely a roller. They did still have flat tappets spec'd around that time too.

 

[supton]

After checking TV adjustment I wonder if dropping the pan and installing a shift kit is worthwhile. Maybe it has one, and it's just not to your liking. At the same time, since it's a recent rebuild, I wonder if dropping the pan & doing a fluid change is a good idea anyhow--although 2k is kinda on the short side.

 

[Phishin]

Originally Posted By: Duffyjr


It also had a new/rebuilt transmission put in right before I got it and has about 2,000 miles on it now. At first if shifted hard but has smoothed out a lot. The thing is it shifts into over drive around 37 mph which I searched and found out this is normal for this setup. Lately when driving around town I decided to run it in drive in stead of over drive but it goes back to shifting hard, especially when it downshifts. Just not sure why it would do this, why would if shift different from being in overdrive vs drive? Do you think it will eventually smooth out? Sorry I'm not sure what transmission is in it but it shifts off a TV cable hooked up to the throttle body, I think its a 700 something.


My 1990 does this too. I drive around town with the OD off, because my old tired truck tends to "lug" when going 38MPH in OD....just doesn't run as good.

I drive up to 55MPH in just regular Drive and if I start to go over 55MPH, I take my foot off the accelerator and shift into OD. No issues here.

Your 89 has a TBI set up. Just like mine. Brand new the motor only makes 190HP maximum.

Make sure your TV cable is adjusted properly. There are plenty of websites and videos on how to adjust it. It's QUITE easy.