if i put 180 cc heads on my LT1 what kind of HP can i expect? and how much MPG can i expect to loose.

 

You shouldn't expect to lose much MPG unless it makes you want to be in the pedal all the time, that's only 5cc's bigger than stock. And there's a lot more to heads than just intake runner volume. You can expect to lose some low end torque because your flow velocity. As far as HP goes that depends on how well the heads flow, what the combustion chamber volume is to determine compression, if you chose unwisely you could have lost power. So get us some more info on the heads and we can make some estimates from there.

 

is putting 220CC on a daily driver a bad idea?

 

It's not necessarily a "bad" idea, it'll still run, but you'll definitely notice the difference in the low end torque with a 220cc head. If you aren't planning on stroking it in the future you'll never be able to use all the flow of a 220cc head though. I'd suggest going with a 195cc LT4 head from AFR and get an LT4 intake manifold and have them port matched for a good flowing street head/intake combo.

 

if i go with the 195 AFRs, would i neeeed to change the intake manifold? would i need to port match to what i have now?

 

The LT4 intake manifold has intake runners that are .1" higher than the LT1 manifold to accommodate the LT4 intake ports. You may be able to see if a shop could do a good job at porting your LT1 manifold to match, but the metal on the top is going to get pretty thin. I would go for the LT4 manifold to be on the safe side, but it can't hurt to see what a shop can do for you.

 

You'd probably do alot better to save your monety for now and buy a good intake, some exhaust parts and maybe have your stock heads ported by a real good machine shop. then later on you can go with better flowing heads and a cam, etc....