well a air cooled vw beetle is very light, stock weight is about 1900lbs, and on engine swaps, u r better off putting in a beefed up vw engine than a suby one, although the subaru engine swap is a good option for vanagons due to the fact that its already water cooled, meyers manx offers a subaru engine option for new buggys, but its a expensive option when u can look at prices on vw parts on cip1.com and performance parts on cbperformance.com
there is a company that offers a nice bell housing for subaru engines that uses the suby clutch and bolt pattern, i may look it up n post it on here its a very clean way to do the subaru swap
but u have to remember a vw bug came with 36 horsepower on the real oldys and uped it to 40 later, just putting dual webers on one makes it fun at lights lol
when u get a turbo kit on a bigger engine in the 2.0 range its hard to keep it from popping wheelies, I got maybe 100 horsepower in my bug just bolt ons and i have broken 3 front transaxle mounts had to strap it on with a metal strap, and i only have a 1.6 only put the bolt ons on it for reliability reasons, all i do for maint is brush the plugs change the oil and keep the carbs in sync, and every few yrs i adjust the valves, but the type 1 vw engine is capable aspiring alot of power, especially considering it dont have to lug alot of weight, but best part is it's cheap... sure u could spend 10k on slapping a subaru mod, or spend 3k on a turbo kit for type 1 and if u want more u can shell out 10k on all the other bolt on mods, bigbore strokers etc and still have money left and no radiator leaks ever! lol
but bugs aint for everyone, u feel the bumps
btw I am building a 1962 bmw motorcycle with a 1600cc dual port vw engine also, dunno how i stumbled on this forum lol
oh and theres also the type 4 porsche engine its a good enine if u dont bore it out n do alot of mods it has a stock 2.0litre version
and no the 911 engine aint the way to go, unless sum how u have acess to porsche parts cheap, and i never seen porsche parts cheap, even the 914 type 4 engines cost more....