YAY!! She runs!!
I hadnt been able to get it fired up since I got the head back on, and I must admit it was a bit of a headscratcher! it had spark, it had compression , I did the valve lashes, it had to have fuel because I just bought a new carby!
but I realised I hadnt remembered to line number 1 plug on the dizzy with TDC when I put it back in! she fired pretty much straight away and runs smoothly.
I love the sound of that weber!

tom,checked that gregory's again for you,the a14/a15 has 37 mm inlets & 30 mm exhaust valves.i can remember years ago a friend put a14 inlet valves into a 1200 gx head,but didn't worry about the exhaust as they weren't big enough to worry about.this sorta corresponds to the sizes above.apologies for the blunder.

My experience tells me that there were 2 different 120Y gearboxes. I think it was the idler gear shaft had bushes and another had bearings. The bushes and bearings were different sizes. So it's not just a matter of putting bearings in. Although you might be able to get replacement bearings to suit.

Sorry I have no information on how to tell the difference externally. Just something I thought I'd share on this gearbox discussion.

Chris.

tom,hi i'm paul.the a15 valve sizes are from a gregory's for the 120y,which also lists a13's,a14's & A15's.so if i can't trust the gregory's that doesn't surprise me.as for pictures of my 1000 & the 1200's,the scanner is here,i just need learnin up on how to use it.also have the video of me rolling my 1200 at huntley colliery hillclimb,so one day i might figure out how to download that.wayne,as for the gearbox theory,that was past on to me from someone in south aus who made close ratio gearsets for the 1200 boxes.as i personally blown up both 1200 & 120y boxes,i much prefer the a14 sizes.surprisingly,yes,the only a12 box that seemed to last was a 120y 4 speed,but this was in front of an a12,not an a15 like the previous ones.the theory was the needle roller in the 120y box was a limitation.

I have to disagree about the strongest gearbox theory. The 120Y is definately the stronger 4 speed. It has bigger bearings, wider gears and extra internal webbing to stop the case twisting. The factory developed the 120Y box from what they learnt racing the B110s in the early 70s. They even went to the trouble of homologating the 120Y box for the B110.

also show us some pics of your 1000!
I dont believe we have been introduced, so my name is Tom.. is there something I can call you other than b310gx? ;)

I would eventually like to rally my b10 maybe.. the only concern is getting strength into the body seeing there are no strut towers to brace...

*dreams of toyota 4ag powered datto*

you might want to check those valve sizes you gave me b310, as my 1000 manual lists the A10 as having 35 & 29mm inlet and exhaust valves respectively

hokay,here's my best guess,the two 56a boxes are a12 4 speeds,one first with ribs is 1200,the second with no ribs is either 120y or sunny.the second 'reversing light'switch is a top gear switch for emissions.this turned off the vaccum advance to the distributor in any gear but 4th,note the different spade connections so you can't get them mixed up with the reversing light switch.the third box is just a 4 speed that is worn in the shift mechanisms,this allows the shifting rods to go into a position where there isn't really a gear.have been caught once or twice myself in wreckers with this one,but a quick check of the actual box put me right.the gearbox is still alright to use,just don't try to flat change into 5th.the way to tell an a14 gearbox from an a12 is the distance between the bellhousing( the part that bolts to the engine) & the front bulkhead of the gearbox (the part the throw out bearing housing bolts to).this is longer on the a14 boxes,4 or 5 speed,resulting in a clutch fork with a right angle at the end.if the clutch fork is there,this is another quick way of checking what type of gearbox you have.yet another way to check is to just pick the thing up.the a14s are heavier enough that you notice the difference in effort.i've been told the best gearbox to use of the two a12 boxes is the 1200,as it has a stronger bearing were the cluster gear sits in the front bulkhead,not a needle roller like in the 120y or sunny(b310).i've been told these early boxes will take 200 hp,though i've never seen this myself.

Cheers for that info olboy. So you reckon the smooth 'box could be a stronger gearbox ...hmm..thats a bonus.

I check the ratios as you said, and they were pretty close to the factory specs for a four speed, give or take for my dodgy readings:

1st - 3.75:1
2nd - 2.1:1
3rd - 1.4:1
4th - 1:1

This is where it gets interesting

Apparent 5th - 2:1
Reverse - 2:1

So its not a 5 speed and reverse gear is too low, shouldnt it be about 3.64:1 as the book says? I take it that this means that the gearbox is shagged as it has a 5th where there isnt supposed to be one. Any ideas?

the box with the webs on it is probably 1200 or 120y and the smooth box is from an A14 SUNNY and its a bit stronger I think but the other one i don't know about but it could be a 5 speed. Try turning the input sharft and count the turns on the other end. put an old clutch plate on the sharft to count the turns
hope this helps