Part #'s posted were for the straight axle HD 3500 and not applicable-tat's why I deleted the post before we knew what axle the truck had.

These are the correct #'s:
FRT ACDELCO Part # 5405033 - 1 per box
Rears with helper spring-ACDELCO Part # 51922-2 per box

 

so ac delco are the best ones to use?> that was my question

 

Seems to me that the originals last the longest.

 

That seems to be my experience on most parts also. Except the engine oil cooler lines. I've never had a set of OEM style, GM Ac Delco or aftermarket that lasted for any amount of time without leaking

In addition to the 2 excellant sources for engine oil cooler lies that Racer mentioned, inlinetube.com

 

Ya-Lubrication Specialists or Leroy Diesel for plug and play or DIY is better than stock when it comes to oil cooler lines.

 

ya i bought a set of oil lines from leroy, havent put em on yet