Dave- as tall as your hiboy dentside (and other lifted) trucks are, do you just crawl in there and work or do you have a topside creeper? They were real popular with guys on the dieselstop. Before my back got bad, I used to just sit right in the engine compartment to work on the old '78. I had two endoscopic spine surgeries three months ago, and I don't see any way I'm going to be able to do work on my old F150 or my Excursion without one. I saw northern tool had the foldable one on sale. Not cheap, but if it saves me from some back pain, worth it, no?
Actually from some recent data I've read... I'm not so sure about that. I was researching the subject and found a writup about the truck 351M/400 not getting the retarded timing gear set.
I had a 3 possition timing set ready to go in case I needed it but the one in there is tight so I'm just gonna leave it be.
Like I said, I have believed that to be true for many years, I think it was just last week that I read about the trucks retaining the same timing set that was on the early cleveland engines.
I dunno... don't care I guess.
It was starting to miss a bit accelerating moderately through the gears towards the end here.
So, just running clean and smooth is going to be the kind of improvement I'm looking for.
I also noticed that when I pulled the intake... Well, par of pulling the intake was unhooking the fuel line from the carb. I expected a full fuel bowl to drain out since these carbs feed the bottom RH side of the bowl. I didn't get much that drained out though. So I was suspicious of power valve. Then when I lifted the intake off the heads, I had fuel running out of one of the intake runners.
So, yeah.. Bad power valve too.
Collectively I believe I'll see noticable improvements.
Yep, I've rolled around in that for info in the past. I found some deeper info too though.
Here's a snip quote that contains some info about the cam timing like I mentioned yesterday.
Originally Posted by bubba
As Ford planned a MY 1977 makeover for their light-duty truck line, they decided to replace the aging FE 360-390 engines with the M-block 351M and 400 engines. Before MY 1977, the M-block had only been available in cars, and only with an automatic transmission, so Ford redesigned the M-block for its truck debut.
Main bearing support webs were revised, particularly the #3 main (thrust) bearing support web, which was strengthened to withstand the force imparted by a clutch. This redesign for truck applications was the only major change in the M-block�s engine block design throughout its production life.
Several unique parts were developed for truck M-blocks, including flywheels for manual transmissions, harmonic balancers, and truck-specific intake and exhaust manifolds. The original �non-retarded� crankshaft timing gear was also re-introduced on truck engines.
Other than the strengthened D7TE truck block, the truck 351M was basically the same as the car engine, with truck-only 8.0:1 pistons and a slightly different camshaft. The truck 400 also used a truck-only piston that produced 8.4:1 compression ratio, and a slightly different camshaft with more lift at both intake and exhaust valves. In MY 1978, car M-blocks received the D7TE engine block enhancements in their own D8AE engine block.