Phase I.
Build a 1600 engine with stock rebuilt DP heads. Add
a mild camshaft like the Engle 110. Change the intake manifold and carb
to one of the Weber or Holly/Weber progressive two barrell carbs, and change
the exhaust. Most anything is better than the stock. You have to pick the
sound level you want to live with. This will give you a noticable increase
in performance over your un rebuilt stock engine.
Cost, about $500 if you do the assembly yourself.
If you want more (is there ever enough?) go to......
Phase II
Take the engine apart again and go to 1776 pistons and
jugs. This requires machining the case and heads to accept the larger diameter
cylinders. Get it balanced.
These modifications will give some increase, but probably
not as much as you noticed in Phase I. Cost, about $300. Want more, go
to.....
Phase III
Swap the heads for some gonzo ported, big valve ones
and maybe change the carbs to dual Webers. My research puts these heads
at about $750 minimum for the pair. Cost for heads and Webers, about $1,500.
Want to go Mustang hunting? How about...
Phase IV
Take everything apart again and buy a 2110 or 2180 stroker
kit. Have the case machined again to handle the larger crank shaft throws.
Depending on your resources, you may want to go fuel injection at this
point. Probably need a bigger cam to take advantage of the other changes,
too.
Cost, if you have to ask, you can't afford it.
Type IV engine conversion
Type IV engines were most common in busses from 1972 up.
They came in 1.7L, 1.8L, and 2.0L sizes and typically had up to double
the HP in stock form. For an example of doing this type of installation,
go to the home page for this section and click on the article at the bottom.