You can make anything fit anything - if you have either the engineering skills and/or mad amounts of $$$. I admire most guys who are prepared to think outside the box and take on something different, but I'd weigh up what you're trying to achieve vs the end product. If you're running a belt drive engine you have all sorts of options on the table - anything from head swaps to full engine transplants. Instant power gains and not a lot of assing around to get there. The Astron engines are limited to Starquest/Conquest swaps - nothing to sneeze at, but an extra cam and a bunch of valves would make the 2.6 scary (yes, there's the HKS heads but you need to find one and have EVERYTHING that was designed with it to make it work...)