Hi, I was looking into buying a 1989 iroc z 28 with the 350 in it. It has 109,000 miles on it. It has been well taken care of so i hear and the trans is supposidely in perfect shape. My question is do these 350s last a good while on these engines or will the get big problems up at these miles. also... how much does it cost usually to rebuild this engine or the 700r4 trans if sumthing was to happen.

 

How long it lasts really depends on how the car was taken care of.

Rebuild costs...they vary depending on location and what needs to be done and what you want done and how much of it you are going to do yourself.

I just had my 700R4 rebuilt last spring, it cost $550 and I supplied the parts ($300 in parts), every removable part was replaced (except the majors, input shaft and the like)

Again it depends on what needs to be done and what you want to do. A word of caution, I have heard that some trans shops will leave the old sprags if they look ok, It is best to replace these, weather they look good or not (not very expensive anyway).

 

If the GM sbc engine & transmission were not any good, why are so many of them running with high miles?? Because they are good and bullet proof in most cases. Worry about repairs when they are needed. Any 14 year OLD car may have problems. I have
one thats 16 years old.

 

The original 305 or 350 TPI engines will last a very long time, as long as they have been well maintained and not been beaten to death. I myself, before making the purchase would try to do a compression check, and make sure the oil pressure is good. That can give you some idea about how the engine is. Also since it has a roller cam, It will not flatten out over time like older chevy engines did and cause them to run bad or be powerless.
If the engine does need to be rebuilt at some time, Small block Chevys are usually the least expensive to rebuild. One word of caution, It seems everyone is selling their Iroc with a 350 in it and when you check the Vin# it turns out to be a 305.
Good Luck!

 

i have had three 350 thirdgen's and none had or needed engines, tranny's, or rear end rebuilds..

i guess i bought them from owners that took fairly good care of them.

 

Did you take good care of them???

 

I agree with the first reply. I bought mine at 112,000 miles and the engine had already been replaced. Of course the dealer didn't tell me this, or that it had an internal coolant leak. Ended up replacing two heads. Since then it's running fine and it has been very dependable. I'm one who takes good care of his things and I want this car to last me forever so just like he said, don't beat on it so much and you'll have less headaches.

 

I bought my GTA when it had 200,000 kms on it (not sure of how many miles that is) and it still feels powerfull as hell at 240,000. I have had to rebuild the tranny, replace the entire cooling system, and other general maintenance, but in the long haul the engine still runs strong (burns a lil oil) and gave me a 14.5 at the track (on the blown tranny). Can't wait till next season to see what the new tranny (shift kit, corvette servo, ungraded clutch packs) and sfc's will do for me. Good luck on your purchase, I know I don't regret buying mine for one second.