Ultra Slow
Well-known member
I have had my 89 down most of the year changing the dreaded exhaust manafold gaskets, for the 2nd time in my ownership of this car. It usually does not take me this long, but I had a son in Feb. These gaskets always seem to develop a "tick" over time, even with me tightening the manafolds up every few hundred miles and running the best fel-pro gaskets recommended in the maintinance manual...... Might have something to do with the extreme heat, but still, these are not "blackjack" headers and "mr gasket" gaskets from Supershops (for those that have been there, done that)! I think if you never race your callaway, you wont see a problem with these gaskets, but if you put pressure on them alot, they will blow eventually. If they do have a leak...Dont drive the car untill you fix as you will be burning parts up where the leak is.
While it was down, I installed a set of crane gold rockers and hardened guide plates, new plugs, and basic thing along that line. Since it was apart, I also got to retorqe the heads a bit... Something that I highly recommend on a callaway that is pushed to the limits.... Although the things I did should have made no difference in power with the exception of the less friction on the rockers, my "banging" out above 5000 RPM problem is now gone, allwowing the car to pull very hard to near 6000... Kind of amazing for an L98, but the big runners are the key there. The car has actually had this banging out issue for many years, and I never had to deal with it due to the fact the car was so darn strong up to 5000 RPMS, unless you were competing with some major race car and needed the last few RPMS. I thought I was blowing the plugs out above 5000, but more than likely it was a plug wire/spark plug issue brought on by the leaking exhaust manafolds that were blowing on #'s 6-8 down in no-mans-land. I took the car for a spin, and amazingly it now will grunt the spec 4 clutch for a second, grab and and break loose the 315's in 5th gear at well above 100MPH with about 12-14PSI of boost, causing the car to step lanes a bit..... Enough to get you killed should you be in a turn or not expecting it at these speeds. The things I did seem to help the car in all areas, and it makes since now after finding out the problem. The car pulled very strong to the mid 180's in just a matter of seconds on the "test track" without batting an eye, or even really wanting to go that fast. I am certain the HP gains on this "urgrade" are at least in the 50HP if not more range, but I will find out for sure on a bench racing day. I am planning on making a show at the "monster mile" this year, even though they are doing it way down in S. texas
While it was down, I installed a set of crane gold rockers and hardened guide plates, new plugs, and basic thing along that line. Since it was apart, I also got to retorqe the heads a bit... Something that I highly recommend on a callaway that is pushed to the limits.... Although the things I did should have made no difference in power with the exception of the less friction on the rockers, my "banging" out above 5000 RPM problem is now gone, allwowing the car to pull very hard to near 6000... Kind of amazing for an L98, but the big runners are the key there. The car has actually had this banging out issue for many years, and I never had to deal with it due to the fact the car was so darn strong up to 5000 RPMS, unless you were competing with some major race car and needed the last few RPMS. I thought I was blowing the plugs out above 5000, but more than likely it was a plug wire/spark plug issue brought on by the leaking exhaust manafolds that were blowing on #'s 6-8 down in no-mans-land. I took the car for a spin, and amazingly it now will grunt the spec 4 clutch for a second, grab and and break loose the 315's in 5th gear at well above 100MPH with about 12-14PSI of boost, causing the car to step lanes a bit..... Enough to get you killed should you be in a turn or not expecting it at these speeds. The things I did seem to help the car in all areas, and it makes since now after finding out the problem. The car pulled very strong to the mid 180's in just a matter of seconds on the "test track" without batting an eye, or even really wanting to go that fast. I am certain the HP gains on this "urgrade" are at least in the 50HP if not more range, but I will find out for sure on a bench racing day. I am planning on making a show at the "monster mile" this year, even though they are doing it way down in S. texas
