Oil pick up

[Turbobus]

Well, got a replacement block for the one I built and installed then found that it had a crack on the outside right bank. Got it vatted machined etc. the block is a 1977 440 block but it has a 1/2” npt oil pickup tube. My 400 and the cracked 440 had 3/8” npt, I understand why Chrysler did it, I just don’t know why this block has 1/2” p/u,,,, any ideas?

 

[Outsider]

Sounds like it was someone's race block, drilling the oil pick up to the half inch "Hemi size" is an age old oiling system mod. Look for tapped holes for restrictors in the deck to head rocker shaft oil passage. How about the lifter bores, are there sleeves?

 

[Turbobus]

Sounds like it was someone's race block, drilling the oil pick up to the half inch "Hemi size" is an age old oiling system mod. Look for tapped holes for restrictors in the deck to head rocker shaft oil passage. How about the lifter bores, are there sleeves?

No tapped holes on either banks and no sleeves in the lifter bores. Have no history on this block. Probably just someone’s modification.

 

[BSB67]

If it's truly 1/2" NPT (verses the factory straight pipe thread), be careful when you tighten the pick-up as the tapered pick-up will more readily crack the pick-up boss on the block.