Oliver Question

The Super 99 head (same as GK195U and similar to MF1100) is the best 9 port head for the Oliver---best meaning highest flow potential. However, a few things need more attention to make it work on the 88.

1) push rods will need to be longer than stock 88, due to tall height of this head.
2) S99 has a stock 1.875 intake valve with a stock 1.4 rocker ratio---so the largest valve lift you can ever see is .450 with .020 lash. This is a poor valve L/D ratio (curtain area is smaller than valve area at peak lift). To make these heads really flow, you need to be at least .530 lift (can do this with JD 4020 rockers 1.65 ratio) with .650 lift being the best (a 1.9 rocker ratio).
3) Max intake valve size is 2.08, but I would not recommend going this big since the cfm per square inch falls off rapidly due to shrouding. If you have a small bore engine (less than 4 3/8), I would recommend staying with the stock valve size. I run a 2.02 in my 88 with 4.42 bore, and have determined that to be the best size---flow does not fall off all the way up to .700 lift (L/D=.35---which is still shy of the best NHRA ProStock motors running 2.515 intakes to 1.05 lift).
4) There are two different chamber sizes on the S99 (GK195U)---one is about 150cc and the other is 129cc. Depending on your CID, you could see up to one point in comp ratio change between each head. The smaller chamber head is better obviously--that is why the MF1100 is so popular, it only came with the small chamber.

Good luck with your project.