Bouymaker: Thanks for the info. I'll use the pre-54 bell housing. I can now see why the sheet metal is yellow. Unit was probably a crate motor swapped into a '56 or '57 truck. So far I have seen no rebuilder's tag but I'll keep looking. I wonder if Chevrolet just painted everything orange in the replacement engine department. Both the head and block are orange, everything else is yellow. For some reason I dislike orange. Maybe it dates back to some ill-fated hot rod of my youth.
Paint: Dear me. What color. Loadmaster Grey to match the 51 Truck? Not much else is factory '51 so it probably doesn't mater, at least to me but I'll be dead before it sees another engine change (I hope) but the next caretaker might care. I've been trying to wear it out for a long, long time but haven't succeeded yet. So far I haven't done anything that can't be returned to factory easily. Just fill some bolt holes and repaint it with the original wheels.
I've been running a six-volt starter on twelve volts for about 20 years and it starts fine. I once asked the motor/generator rebuild shop if they could convert it over to twelve volts and the guy said "Why?" That said, the reason for my present starter question is that I want to get away from the 9-bolt clutch and they were only on six-volt flywheels. Those clutches are expensive and a couple weeks away unless I want to drive 500 miles to Vancouver/Portland. So a 12-volt starter and flywheel solves several problems. I followed up on the thread about clutches and I'm satisfied that the six-bolt clutch will fit inside the old bell housing. I wondered because last time I changed the nine-bolt clutch it was really a tight fit, holding the clutch assembly with one hand while threading a bolt in with the other.
FWIW some years before the last clutch change I used an 11-inch V8 clutch disc as I couldn't get the 10-3/4" inch locally. It worked but the clutch always juddered on take up. I think that was because the V8 disc had a different number of torsion springs. I don't remember if it was more or less springs but the six-cylinder clutch has always been very smooth.
HRL: Thanks for the heads up on the valve springs. I'll use the valve rotators. Wish I'd had some last time the head was rebuilt. The shop put in stainless valves and seats but recommended against stellite seats. I did get bronze guides, though. That head has been in service about 40,000 miles and cured the constant valve adjustment problem I'd had before. So I'm tempted to use it with the addition of the valve rotators and springs.
Exhaust valves on heavy-duty gasoline truck engines have always been an issue. Years ago I did a valve job on a 322 Lincoln out of an F8 Ford. It required several new sodium-filled exhaust valves. The shop foreman cautioned me to never try to make a center punch out of a sodium-filled valve as it would explode when I cut the head off with a torch. I encountered those valves on 392 Internationals and 534 Fords. Mercedes/Thermo King diesels had them, Mercedes cars too. I don't recall them on GM engines, though. Probably overkill for a 261 Chev even if they were available.
So, today I'll pull the head and see what's under it and maybe a valve or two if I can find my valve spring compressor. I'll keep you posted on what I find that's interesting.
