425 pickup tube in a 472

[68C15]

I have a 68 472 that I am installing a 425 pan & pick-up tube into. I see the 472 has a 5/8 tube while the 425 had a 3/4 tube. I also noticed the hole in my block has a step in it which registers to the 472 tube. I need to enlarge the hole. should I just machine the full depth to 3/4 or what? should I enlarge the feed hole going to the pump as well? what size?
TIA, Todd

[fleetwood472]

Ya I think you just bore the hole out to 3/4 like on the 425. It probably wouldnt hurt to port the oil pump passages either. - Justin

[burnrubber]

If someone were buying a 472 (that had 425 pickup) from someone to put in their fleetwood, deville, ect.. they wouldn't be able to reinstall the front sump pan and pickup tube right? This would be some helpful info to anyone looking to buy an engine for their RWD Caddy.

[fleetwood472]

Ya they can but they just need to bore the pickup tube out slightly. Not a real involved job. You can just have the machine shop do it when they are doing your other block work. - Justin

[STDog]

I belicve the 5200 blocks are the larger size. I had no issed with a '72 coupe that I put a 425 in recently. The 472 pickup fit just as snug as the 425 pickup did, and I stored the 425 pickup in the 472 block and don't remeber any fit issues.