I have a few questions about my 89 Honda Civic HB base model
1. Does the base model and Si have the same block, so i can just swap heads?
2. If i do a Si head swap, what tranny should i use for drag and highway use? same, DX or SI tranny?

 

1. Does the base model and Si have the same block, so i can just swap heads?- The blocks are diferent sizes Si = 1.6 and Dx = 1.5 But you can swap heads. Try a search for mini-me swap this has been posted a million times

2. If i do a Si head swap, what tranny should i use for drag and highway use? same, DX or SI tranny? As far as trannies the Si is better for drag but it screams on the Freeway. Great for racing the .Dx is alright to use but it is geared more for gas mileage

 

i've had a better time with a dx on the freeway cuase the long gear on third
while the other person is shifting your still pulling past him on third

but it does suck on the track and the si is vise versa
just my $.02

 

ABSOLUTELY!!! I kept my Dx tranny with my D15b7 swap(JDM 1.5L SOHC Vtec Not Vx) all I did was upgrade my clutch to stage2 and man on the Fwy I'm damn near untouchable. Third gear is insanely long and pulls hard especially in Vtec. But as far as nose to nose dragging it leaves a lot to be desired. But mine is a commuter so I like the gearing of the Dx

 

i have a ? due to smog ref.. i had a jdm 1.6L soh vtec (zc)...but have to put on non-vtec head for my '91 Si hatch. i put on head from junkyard. the head was supposedly pressure tested/resurfaced, new head gasket. I took my sweet time putting this on [bracket under the IM & timing belt were a beotch]. its hooked up with a crane & ps92....barely turns over..very rough like less than 500rpm for a few seconds.. then DIES had it towed to a shop to adjust the timing belt..for 91 si, but they said no comp/spark in #4 cylinder. i checked the ecu and its blinking a code 10 . HELP !