Reg. to HiPo

Hey guys, this is my first post here, but I'm used to the routine (I've been at the supercars.net and carforums.com forums). Anyways, I have a 66' Mustang that I would like to add power to. I want to turn it into HiPo spec (we have a regular 289). I was wondering what changes seperate a regular 289 from a HiPo 289 and how much it may cost. It has already been changed to a 4 barrel. About how much more power could we get with the change (have some other, small mods). We also plan on getting a newer exhaust system with free-flow headers. Any help would be appreciated, thanks.

Welcome to the forum:)


The HiPo (A code) 289 has a 4bbl carb and higher compression than the C code 289 and is rated at 271 HP.

You already have the 4bbl carb, what sort of 4bbl intake manifold do you have?

You will get the most out of your windsor with a cam change, increased compression, Mild porting and a good set of headers with free flowing exhaust system

We have a Weber carb and a Edelbrock (I think) Street Dominator intake. I thought the HiPos were K-Code.

"I thought the HiPos were K-Code."

Correct, Sorry for the typo:bloated:

Spotted your Stang on "Hot Rides" and its in the top 10 with mine:D

:devil: I got over 240ft-lbs of torque to the rear tires (with an AT trans) with just a little more work than you. If you havent invested in exhaust yet I would look at the flowmaster kit w/stainless tips. I used a cam with the same specs as the HiPo moters but swaped it out for a larger dualpattern cam, Crane Powermax 222/234 .498/.527. Buy new springs if you get a cam. The car is daily driven by my girlfriend so there are no drivability problems. I like this cam much more because it gives such a broad powerband, the car pulls through all rpms. If anything port the exhaust ports in the heads, its worth it but the heads are only good for about 300hp, I wish I bought aftermarket heads. Even with the smaller HiPo cam my 66 droped a 69 Mach 1 390 w/a 4spd, gears, cam, intake and carb And I know he was trying, and that he can drive because it was my cusin, that motor came two days later for a set of alm/heads and better cam. If your looking for a quick boost, try an electric fan, they are worth their weight in gold! If you have any questions ask!!