"In 1999, the more powerful DB7 V12 Vantage was introduced at the Geneva Motor Show. Its 6.0 litre, 48-valve, V12 engine produces 420 bhp (309 kW) and 400 ft·lbf (542 Nm) of torque. It has a compression ratio of 10.3:1. It was available with either a TREMEC T-56 six speed manual or a ZF 5HP30 five speed automatic gearbox."
and....
"The Vanquish is powered by a 5.9 L (5935 cc) 48-valve 60° V12 engine, which produces 343 kW (460 hp) and 542 N·m (400 ft·lbf) of torque. It is controlled by a fly-by-wire throttle and a 6 speed 'paddle shift' or semi-automatic transmission. A special V12 Vanquish S debuted at the 2004 Paris Auto Show with the power upped to 388 kW (520 hp) and 577 N·m (426 ft·lbf).
The Vanquish's V12 engine shares some components and design elements with the 3.0 L Duratec 30 V6 from parent-company Ford. It even shares the same bore and stroke dimensions. For this reason, many people incorrectly dismiss the Aston Martin V12 as merely "two Duratecs linked together."
The V12 engine in the Vanquish was designed at Ford Research in the USA. Cosworth Technologies was originally contracted to manufacture the engine, but had no involvement with the design. Previous articles which correctly recount this engine's development have appeared in Automotive Industries magazine.
It is correct that the AM V12 shares components with the 3.0L 'Duratec' V-6 engine used in the Ford Taurus, but it is not possible to simply put two V-6's together to make a V12. The bank offset for a V12 is equal to one rod bearing width, whereas the bank offset for a 60-degree V-6 is significantly longer than one rod bearing width, thus it is necessary to design a V12 as a totally new engine."
found these photos........
if you can get a reference dimension you can scale it and measure.....
Doc Watson