i got a d16 with all the basic bolt ons headers, intake , throttle, and manifold.. done but car still has no top end speed lags after 90ish any suggestions on maybe a problem or anything?

 

Sounds like a normal sohc civic to me.

You just need more power.

 

how much would it cost average to do a swap wat would be the best for a 99 civic ex.? dont know really too much just only had it a couple months but would the si motor bolt up to the transmission car? and would my headers and ect. bolt on to a si motor?

 

No, you need everything from the SI.

Japanese B16 swaps run about $2500 if you install them yourself.
But '99-'00 SI swaps are more expensive if you can find them.

 

another thing i was thinkin is the d16 worth putting a turbo on?110,000 miles on the car would i need to change pistons u think? cause i just got the head rebuilt.? juss tryin to go the best route

 

Sohc turbo can be very potent.
Assuming your block is still in good condition, a low boost set-up should be ok.

 

that actually sounds prob the best.. way 12-16 psi