there are many reasons that the shorter stroke/bigger moter is better-------better rod angles, better breathing as its hard to fill the bigger engines with the heads that are reasonably available---

The Vega chassis is lite enough and wheel base good for good consistant launches with only a moderate change or two-----most important (considering that ladder bar/four link bars) will probably be spring and shock choices---the car will leave good without all the body roll, wheel spinning problems of a big block and still run 9, 10s at 140-150mph with either small dual quads or one big 4 barrel--------