Yes it is!!!! Vintage from the 70s!

The problem I will have going to adjustable rockers is the fact they are not a conventional stud-mounted rocker. They are LS7 exhaust rockers on all 16 valves.
I guess I will need to point this out to my cylinder head guy when he does the valve job so he keeps the valve tips where they belong. If it works for the LS guys... I guess it will work for me too. lol

And yeah... I will probably just keep the metric stuff where it already is. It's easier to source metric hardware than to re-thread every hole.

It's my understanding that these PSI blocks are in fact standard threads in the mains... so that part is easy. A regular 4-bolt BBC main stud kit will work.
Only oddball part will be the metric head bolts/studs... but I see ARP has that covered also.

Sofar... everything ive read that is related to these PSI blocks is that the mains are in fact standard 1/2-13 threads, but the head bolts are metric.

I havent snatched the oil pans off these motors yet to confirm... but eventually once I have them home and on stands, I will tear them down and make notes of all the oddball details to update this thread for future benefit to others. The internet info will long outlive me.

Another anomaly popped into my radar...

Anyone know what crank sensor this engine is compatible with ?

The GM 8.1/496 has a 24x reluctor on the crank and any off the shelf 8.1 sensor works in that application...

The latest PSI engines use a 58x reluctor with a 1x cam sensor.
Anyone know if the standard 8.1 24x crank sensor will also work with the 58x reluctor ???

Thats a great question for Cerberus66 or call Larry. Even with the standard Merc 496/8.1 the part numbers changed from early to later models so you need to be careful with that one.

However, arent you doing a swap? If you swap your ECU and harness cant you use the same reluctor ring or at least buy the same one?

Yeah one of these will be replacing the current Volvo Penta 8.1... so if I need to swap reluctor rings... its an option.
Trey swears by the Holley engine mgmt system... so that may be the route I go, depending how things shake out.
I have a local guy that insists he can access and program the Volvo Penta EGC ECU.
He is booked until January... so I wont know until I get him out to plug into it.
If he can hack into the ECU, it would save alot of headaches, time and money.

Just realized you are in GA, are you on Lanier?

Yessir. Sorta.
North end near Gainesville Marina. Not "on" the lake but 8 minutes from a boat ramp.
Property on the water is insane money.

I know, lived in Gainesville off 60 directly north of the 60 bridge on the little point that sticks out. 2005-2008

At that time, the lake was down like 30 feet or something. I left and that lake has been at or over full pool since then. Ridiculous. Have 2 good friends on the lake on the Dawsonville side. Was just up there for Petit Lemans at Road Atlanta. That lake is a good time!

Before reading this thread I would have passed over a boat with 8.1 power. I have a whole different viewpoint now, great thread and great info.