Hi Dauntless, The shop manuals
tend to cover several years. Until you become familiar with the changes year to year, it's very confusing. Shop manuals
were written for experienced dealership mechanics. All these differences were passed down word of mouth to new hires.
Triumph made many changes year to year, even many mid season changes. Some well documented, many not well documented, but are known by experienced owners in BritBike group.
'67 would be considered the last year of the "early" unit motors. No provision for strobe timing. So setting timing takes a bit more skill. Clutch cable changing is harder as there is no access hole to cable end in trans cover.
'68 was a transition year where many changes were made. By '69 these changes were mostly completed. Primary cover with timing marks for easy strobe timing. Improved push rod tube sealing.
'70 got different crank case breather system. Primary now shares oil with motor crank case. This motor ran through '72 with various minor changes until Triumph morphed it into "short rod" 750. Got various reinforcements & a 5 speed.
So it's going to take some time & study. The motors sort of all look the same, but there are many non interchangeable parts from year to year. So you may need to change other parts to make a non '67 part fit. Not a big deal, just so you are aware of this stuff.
Here's a link to parts books. http://vintagebikemagazine.com/links/parts-books/
Keep in mind Triumph changed thread system from British threads to Unified threads. We'll know them as American threads. Most SAE fine thread. So the exact same casting from '67 to 68 or 69 will have different threads... The threads are close visually so a thread pitch gauge is helpful. NEVER EVER force a thread. If it doesn't go, figure out why. Is thread bent or is it different thread. Screw heads are often pozidrive with 4 tiny hash marks between slots. Google it. Philips doesn't fit right. You'll need "Whitworth
" socket & wrench
set. A few American sizes fit, but most don't, nor will metric.
For motor use any brand motorcycle oil you want. Higher the zinc the better. Most car oils have low zinc & friction modifiers. Zinc tends to greatly reduce cam wear. Most car motor oils makes clutches slip. So no 20w car oil in primary.
In primary use ATF-F. It gives good friction, good chain lube & reduces clutch slippage. Dexron works ok also. But doesn't give as much grip. ATF-F is getting harder to find. Orielly's Auto parts by me Pleasant Hill, CA stocks it in house brand. I've used it several times. Works good. If you think grip is too hard or notchy, try Dexron II or III. It'll calm it down. Personally I think the F is better long term as it reduces slipping. Use level check plug on primary cover per shop manual
to set level.
Trans oil was 50w. Now it's better to use 80-90w gear oil like cars put in differential. However.... It must be non ferrous metals compatible. Some GL5 fluids will erode our bronze bushings inside the gears. Stay Lube 85w-90 gear oil is what I use. A bit harder to find. Advance Auto Parts stocks it near me. Some other private label parts houses stock it also. Drain trans. Fill with 500cc through plug on top of trans.
The cheap Gerber plastic baby bottles at Target or grocery stores were perfect for measuring oil. They are marked in both oz & cc.
You may find owners handbook very helpful. Buy repro or original if you don't have one. I don't have link to '67 manual