I have a 98 Blazer with a L35 engine.

If I replace it with a rebuilt GM engine does any one know if a timing chain tensioner is recommended? The local dealer parts department does not know anything about it.

I understand that GM had a tech bulletin at one time about putting one on this engine.

 

My understanding with GM Goodwrench engine or transmission that any improvements that was implemented for your application has been applied. I have both a GM Goodwrench Engine and Transmission in my 89 S15 and I have had no issues with either one. I know my engine did not have a timing belt tensioner installed. I installed the engine myself. I have close to 100K on the GM Goodwrench Engine.

 

I decided to pickup a GM remanufactured engine for my 98 at the local dealer since my engine had spun a connecting rod bearing. Mine could be rebuilt but I need to get it back up quickly and the dealer price was within $500 of my cost for machine and parts. 3 year , 100k warranty included.

It turns out that the GM engine uses the same silent chain style timing chain as the original. I had 154,000 on it and it never made any timing chain or balance noise.

After some research it seems that the tensioners are only used with roller style chains.

If I rebuilt the original I think I would consider a double roller chain and a tensioner. But I still have my doubts that it is really needed since I have built a bunch of small block V8's and never used one.