Hi there,

I have reasonable mechanical knowledge but limited practical
experience working with mini engines so I thought that I'd pen down
what I intend to do and throw it to the floor in case there are any
faux pas in there.

I've got two A+ engines:

"Blue"
12HE25 (Metro 1275) block
Stage 1 unleaded mini head
Cracked diff housing

"Red"
12H996AA (MG Metro 1275) block
MG Metro leaded head
Good gearbox/diff casing

My plan is to move the good head from the "Blue" engine onto the "Red"
engine to make a runner. At some stage I'll then replace the bottom
end of the "Blue" engine to get round the cracked diff housing
problem.

Now the questions start:

Does it matter which push rods I use? I'm guessing that I should use
the "Blue" ones as I'm using the "Blue" head.

I'll need to sort out the rocker/valve clearances and plan to use
values recommended for a 1275GT mini engine as this is comparable to
the head. Sound about right?

I'll need to adjust the timing. I'm guessing that I should use the
value recommended for an unleaded 1275 engine (say a later MG Metro).

Is there anything else that I should be wary of?

Thanks for reading this far!

     - James