I'm putting new -1's on my block & I'm upgrading from the -4 external lines to -3 this time around. With the -4 lines I had a restrictors in the line to control oil flow but because the -3 lines are so much smaller, I'm wondering if I even need to have restrictor. I'm also updating the rocker gear to HS if that matters.

You could try it without them and add them after later if needed.
I use a .039 hole size on all my Indy headed motors with Harland Sharp and T&D single shaft roller rocker arms
Are you planning on running a solid roller cam with it? If so those valve springs need all the oil they can get on them to help keep them cool
How big is the oil pan capacity ?

I had a similar sized hole mounted into my -4 lines Cab. They worked well but at that stage I was using ICH shaft mounted rockers which I felt didn't need as much oil as the roller bearing HS units. Yes I'm running a mech roller cam with nasty big butt spring pressures. The oil system runs 14 quarts when full & that includes the accusump.

I think you will find that the extruded aluminum rocker arms like the Crane and ICH don't allow as much oil flow from the shafts as the true needle bearing rocker arms like the Harland Sharps do
Lot more room between the needle bearings than from the close fitting extruded aluminum rockers, there is a lot less contact surface also to restrict the oil flow

This is the finished result. I'll see how much oil floods off the rocker gear when I do the prelude on the cordless drill. There's quite a difference in size between hoses.

I would think you will still need to add restrictors. We run .046 restrictor in ours.

Nice lines. Did you make them or buy them? I need to replace my stock rubber lines before we go out with the new car next Spring.

i made these. that Braided line was off the old heads i had. both of my new lines weighed less than that 1 braided line. i think i'll be replacing all my Stainless braided lines to Race hose in the future.

I've been racing with no restrictors for 4 years now. The inlet on the head is 1/8" correct? I don't think bigger or smaller hoses will do anything but create more volume which is fine.

With Harland sharpes you absolutely need to run restricted oil lines - or you will be pumping way to much oil to the top of the heads and taking away from your bottom end. Usually a .040 is good - but no more than the .060

this is what i was thinking. i used HS on my SB & as soon as i installed them i noticed a drop in oil pressure. the big test will be the prelube on the drill which will happen this week. got the engine sitting back in the car last night. a few more nights n i'll have all the wiring n plumbing done ready for launch.

Same here. Lost significant oil pressure until I dropped down to around a .045" or .040" restriction to get my oil pressure back up to where I started. Still left plenty of oil to the shafts for the HS rockers.

You can run .015 per side and still oil more than necessary...