i eliminate the drain tubues,new shafts and rockers that are in decent shape,use 302  umbrella valve seals,grove deepend cam groves.all rockers get oil,no isues with oil returning ,set valves with engine running. did this with 292 in ranchero was 3yeares on engine when i sold it, used 1 quart of oil i 1000 miles. present  truck 1949 merc with 292y same storey  has 800 miles on re build has 25 psi oil presure at idea hot,55 psi 2000 rpm hot,no issues still does not need oil. so i am convinced with decent valves and guides,along with good rocker shafts and rockers,302 valve seals the only way to go. every y block i have worked on with high miles, rocker shaft and rockers thrashed  at end of shaft away from drains.

Got it.  I'll check that.  Thank you.

Just letting it run with Covers off. It started to overflow the side of the Head. If the Cover was on to contain the Oil it could end up flooding the Valve Seals.

  

Noted.  We will be installing the oil pump and pan in a few days.  The rockers are pressurized with the drain tubes closed about half way.  We'll be sure to check the oil drain back with the engine running. How did you know you had a problem?  Did your engine smoke excessively?

By deepening the Camshaft Oil Groove to .035 You may find the Oil Flow to Head is excessive with the  Oil flowing faster than it can drain .I ended up taking the Rocker Shafts off and tapping and installing a restrictor plug with small Hole drilled in the Plug. I don't remember what size Hole I drilled in the Plug but it still allowed good flow of Oil but not too much that it would build up faster than it could drain.

  

This is the original 1955 292 engine block.   The block had been hot tanked back before the EPA put the kibosh on harsh chemicals.  I don't know how many times it had be rebuilt in the past, but the block was a mess. One side was higher than the other and the crank caps were misaligned.  The block was bored .060, shot-peened, decked and the mains were straightened out. New cam bearings were installed.  The crank and rods came out of a 1957 Ford station wagon with 40,000 miles on it.  The crank is standard.  The rods were rebuilt with ARP bolts and the crank was polished.  The rotating assembly was balanced.  We had a hard time finding standard bearings.

The cam is an Isky RPM 300 with a Rollmaster double roller timing chain.  We deepened the cam oil groove to .035.  The cam degreed in right on the numbers.   The heads are 1957 "G" heads and rockers.  The intake is a 1957 "E" code cast iron Ford 4V with a Holley 1848-1.  This motor is going in a 1955 Thunderbird with 3.89 rear gears, 3 speed manual with O/D.  It should run pretty strong.  We'll see.

I use Permatex.  It's been working for me for 50 years.

I replaced the rear main seal with the engine in the car. I used Permatex Ultra Black instead of the side seals. I was able to fill the voids with the plastic nozzle that comes with the product and wiped off the excess that squeezed out of the gaps between the seal retainer and the block. If I ever do it again I would use Flex Shot (as seen on TV) as it is neoprene, fuel proof and comes in a pressurized container.


"FREE SAMPLE"

I don't think I would personally use RTV for that. There is another Product that some others have used for same Purpose which apparently works very well but less chance of getting loose into Oli Passages. Maybe someone will post that Product. I read somewhere that the majority of Rear Main Seal Leaks are not the actual Crank Seal Leaking but the Side Seals.To replace the Side Seals with Sealant can only be done with the Engine out of the Car on a Stand upside down I would think??