So when i had my lm7 block all cleaned up fro building it, he told me i should use GM main and rod bearings? he said that if i dont the aftermarket ones can be off just by thousands of an inch but can add up. I have the whole rebuild kit already bought and ready to go but im kinda stuck on this, i dont know if i would be fine to run sealed power bearings or go with GM bearings?
Please let me know what you guys think!

 

You need to check your clearances regardless of what bearings you use,, I have never heard of that theory of aftermarket being off as compared to oem,, Some bearings are better than others, I have the king alleculars in mine, But You cant go wrong with Clevite 77 they have been around forever. I think that the sealed powers are made by federal mogul, they have been around for a while also. Check your clearances if they are in spec, you should be good to go.

 

I've also never heard of it either, when I had it all done at the machine shop he said all the specs were good for standard bearings but I will check them also to make sure they are the right specs