Posts: 1,330
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Joined: Feb 2015
The dual plane Procomp intake manifold for 351W motors is a copy of the Weiand Stealth. The Weiand Stealth is a good street manifold design and works very well. I actually prefer it over the Edelbrock Performer RPM. Plus it looks a lot cooler than the Performer RPM. Since you are doing all these other items, have you thought of a camshaft upgrade to take advantage of all the other work done to the motor?
Best Regards,
Mike
Posts: 236
Threads: 45
Joined: Dec 2014
Posts: 1,330
Threads: 34
Joined: Feb 2015
That's okay you decided not to port the cylinder heads. But the rocker arm stud goes straight through into a water passage. The hump in the roof of the exhaust port is solid. If you look at cylinder heads with the thermactor passages it will clear up the mystery. When you pull out the press in rocker arm studs you'll notice the hole goes into the coolant passage. Be certain there is thread sealant on the screw in rocker arm studs or coolant will leak through the studs and ultimately into the oil.
Did you check the piston to cylinder wall clearance on the cylinders with the cracked pistons? You didn't mention where the pistons were cracked. I ask because if the pistons skirts were cracked, the most common cause is too much cylinder wall to piston clearance. This allows the piston to "rock" in the bore banging the skirts against the cylinder wall. Plus your piston ring end gap was slightly too high, or was there another reason for that?
I don't know what those stamped numbers are for. The previous owner may have done that during the first rebuild. Maybe some body else will know. To the best of my knowledge, Ford, unlike GM, never applied numbers to the engines to match the VIN on the cars. Numbers matching for Fords means correct casting numbers and date code that are cast into the block or other parts. And then it can be subjective unless the date code is later than the build date for the car.
You can do a cam swap later, just more work. It would have taken you 30 minutes or less to do it when the motor was disassembled on the stand. Not including replacing cam bearings if they were severely worn.
Best Regards,
Mike
Posts: 236
Threads: 45
Joined: Dec 2014
Clearance was .002. I ended up returning rings and bought another brand which had to be filed.