Originally the A9Xs used L34 blocks and heads from the LHs, however later factory blocks were used because the extra webbing at the back of the block was included.
A9X road cars were stock L31 engine wise.
The A9X also used down draught Webers instead of the side draughts used on the L34s because they had the scoops.
Changes to the CAMS regs were made over the period that the A9Xs were run.
As new shells were built up for racing GMP&A shells were used instead of finished road cars.
You need to chose a particular season of racing to determine which specs to use, ie 1979 spec cars would have been different to 77 spec ones.
James
Edited by JBM, 21 December 2007 - 08:49 AM.