Getting a smallblock to rev

knighty said
Some good replies here chaps, thanks for the effort.

To try and clarify the rules a bit;

I have to use factory cast heads (but in my interpretation, j or x heads are still factory with a trim around the top of the bore??) larger valves can be incorporated.

Be clear here since there NOT 273 heads and they may be illegal to use. Just be sure about this. A 1.88 valve will require a notch in the cylinder bore.

Their wording, 'performance can be improved by the removal of metal'

Porting, heads, intake!

Stroke must remain the same
Bore can be a maximum of 1.5mm over

Who has the mm to inch conversion for this?

Induction, exhaust and manifolds are free as long as they were available before 1972,

Could you clarify this for me/us? "Free?" Free to change and up grade? Then that is sweet!

Roller cam is allowed
decking heads, block or higher compression height pistons is allowed,

OH! MY blood pressure just went up with excitement!

Long story short, as long as the component can be described to run in the same manner as it does factory, eg oil pump uses similar internals and runs off the same part of driveline, there are certain freedoms to upgrade it.

the main circuit in consideratin for the class, as you can see it's overall a pretty fast circuit, lots of top end, most cars in the class are doing this 2.4 km stretch in around 1:04 so 8,000 rpm down the back straight would be a great advantage

Did I mention the oiling mod sticky you need to read and follow?