18hp Vanny upgrades with 16hp parts engine

[pflumph]

Hey all,

I've been researching vanguard performance upgrades recently, and this certainly seems like the place to go for information! Now, I don't own an amphib, but your expertise is certainly greatly appreciated!

I have a golf cart that I have lifted, upgraded and have now rebuilt twice over the last 10 years.

The engine is tired and I'm not rebuilding it a 3rd time. So I'm going to re-power with a Vanguard. I bought a 16hp on Monday, but it turns out it has a broken rod and the block is junk. No problem, I knew it had no compression so I only paid $60 for it.

Then I found an 18hp and picked that up on Wednesday. I need to tear it down to make sure it's all OK (It runs) so I figure I might as well do some upgrades while I'm in there. I don't want to go billet custom 75hp everything, but would like to use any affordable bolt-on parts I can without breaking the bank.

My plan was to pull the exhaust restriction, install a 20hp carb (Preferably the 2 bbl), and install the rev kit - All information I got on these forums. I've read that this will make it stable to 5500 RPM and 20hp.

That's all well documented and pretty easy. But now I've read that I can use the heads from the 16hp vanny for higher compression, and a 23hp cam! After a couple weeks of searching, I've found that there's a LOT less information on these upgrades.

So I have a few questions for you big block guys - All assuming it's a 20hp with the rev kit installed now:

1) If I install the 16hp heads on the 18hp engine, what should I expect to gain? Is it worth it?
2) And if I use the 16hp heads, can (or should) I use the thin copper head gaskets to drop another .030 in clearance?
3) If I swap the cam for the 23hp, will that have a significant impact on performance, and are there any concerns doing that with the higher compression mods?
4) And finally, with all of that installed, would compression be too high to run regular car gas?

Thanks a lot guys for the advice!

[Nubs]

More compression and fuel = more torque.
heads n gaskets, yes
springs n push rods, yes
23hp cam, no.
reground cam, yes
hi torque starter, yes
reg gas is fine

[egoperf]

I have a built 20 hp witch is the same as an 18 hp I run 100 octane. I tried pump gas. I noticed a big difference

[E.TX Mudslinger]

Nubs, What regrind cam do you recommend to use with the above mentioned mods? Who is it available from? What size ?mm Mikuni carb would work best? Would 16 h.p. heads w/thick graphoil gaskets improve torque performance and still allow use of stock starter?