Hi i have a A15 in a sunny wagon and think of put the l20b init or turbooing the one thats in there i can get a turbo charger for about 1200 in this a good price and how mmuch more power will it have or is it worth putting the L20b then makin git efi and then turboing it ?
I also have a 5lt holden ute and that is staring to get slow

mmmm this pic is all wrong... turbo sunny wagon?

Forced induction.
This is a subject that was vigorously & robustly debated in an extensive thread not so long ago, so have a play with the search function & you will likely find it.

Myself, & a few others prefered the ability of the positive displacement blower to deliver high levels of torque, almost instantly, at very low engine speeds, while a large number of others prefered the advantages that a turbo offers at higher engine speeds.
The turbo debate was further broken down into blow through versus suck through.

See if you can find this thread & have a read through it all. With some luck you will gain an insight of the advantaged & disadvantages offered by each system.

Edit. Why is this thread in the 'Meetings' section?

And dude if you want a turbo, I have the perfect one for you. Its a t25 with 3000km's on it and never ran over 10psi. There is no shaft play at all and is like new. Let me know if you want it. and try 250-300 instead of 1200 bucks. PM me if you decide to go the turbo application.