Those articles do make alot of sense. Why do you think that when you run seafoam on a car that uses conventional oil it smokes like crazy.
I only had under 1000 miles on my oil when i read about seafoam and tried it and wow that oil went from near clean to straight up nasty once i drain it. It was the darkest and dirtiest I have every seen Motor oil. So i wouldn't be surprised if all that crap was pluging up any leaking gaskets I had.
I switched to Mobil 1 10w30 at 170,000 miles and it did leak. Only half a quart every oil change. And i usually put about 500 to 1000 more miles on the oil then recommended and running the car HARD.
The way i see it is, Would you like to know whats wrong with your car and fix it then find out to late. I have so many people that come to my job asking for thicker grade oil cause their car leaks to were they even want to run 20w50 and they all have been conventional oil users.
If your to SCARED of running full synthetic go with the synthetic blend Oils.
1994 GT AODE, Performance Automatics Street/Strip Valve Body , 3.55, BBK(H PIPE, Equal Length Shorty Headers, UnderDrive Pulleys -minus Alternator Pulley, Spring Insulator & CAI), FlowMaster Super 44's Dumped, MSD(Distributor, TFI Blaster Coil & 8.5 Super Conductors), Ford Racing B Springs, KYB AJX Adjustable Shocks, AJE(Tubular K-member, A-Arms & 5.0 Solid Motor Mounts), Stiffler Transmission Crossmember, SVE Rear Upper & Lower Control Arms, Explorer Intake, A/C Delete, Smog Delete