- 98 Vortec 350, 4 bolt main

Long story short; I tried to torque down my oil pump using my old 2-piece rear main's oil pump bolt, but because it is shorter than the one I should have had for my new 350, only threaded into about 3 threads before tightening and I stripped out some threads and surrounding material from the main cap while torqueing. There are still 6 or 7 threads left in the cap.

My question is; Is this main cap still safe to use? Is it still structurally sound? I don't exactly plan to baby this motor...

Thanks guys.

 

It's a judgement call but personally, I wouldn't use it on anything but a factory engine.

New cap which will also require a line hone to make sure all the caps are running true. You could risk just slapping on a new cap and bolting everything back up but how much is your rebuild worth?

 

Yeah... this engine is far from factory (around 400hp) and worth a good amount...

Anyone else seen this before?

 

Frequently.

Comes from using the wrong bolt.

No biggie though, easily recoverable.

Heli-coil the cap, and get the right bolt.

It'll be fine. Never know it happened.

 

I recommend a thread insert not a heli-coil on something like this.

.

 

use an oil pump stud

http://www.ebay.com/itm/Arp-Sbc-Smal...-/310650676625

 

The remaining cap threads are OK, would I still need to Heli-coil?

 

no, grind out the roiugh part so there are no cracks/stress risers and use the stud.

 

You will be fine!

 

I went with the stud.

Thanks for the replies guys!

 

this gives the added benefit of being able to smooth things out and port out the oil port a little bit for some extra flow... it's actually something that the better builders do as a part of the machining of the block...

also, make sure that the new stud doesn't stick thru the bottom side of the cap and push on the bearing shell.. that would only end badly...