From checking online on the thumpr small block cams they look to be more on the sound effect with the split high running durations which to me could hurt some of the lowend torque. When I brought down the running duration and brought up the @ .050 duration as suggested by some of the tech guys I felt the tbird react with a seat of the pants pull and I was convinced. Ted is doing another tight lash in my new motor for the tbird as of now, and the first yblock strocker I know of that made over 500 hp runs a similar cam.These are ofcourse larger than anything you would need for your application. This is only my opinion, and what I,ve actually run in the past and currently.

-Gary Burnette-

What are the specs on the Mutha Thumpr?

-Gary Burnette-

Thanks. Will have to take the time to call them. The Mutha' Thumpr cam they recomended has intake valves at .012 and exhaust valves at .014 which is tight by Ford standards.

Comp can cut any custom grind you want if you tell them which one. I have found the Tight Lash series work really well, then come to find out these are very close to some of Iskys grinds that were so popular with the street and strip guys. Talk to the guys in tech and ask about the tight lash series ( Dave and Gordan ) are very good to deal with, tell them I said to give them a call, they should be familiar with the Y-block engines I,ve worked with them with over the years.

-Gary Burnette-

It is my understanding that Comp only offers 3 options for the Y at this time. Not seeing the ones you are talking about.

Years ago I had a talk with a couple guys at comp and was told by them that Ys like higher #s @ .050 and somewhat lower #s @ running or rated durations. The same seems to be with Isky looking at some of their old grinds. This is when you're street and strip,example would be like what it seems you're asking for something like extreme energy comp 236 @ .050 running duration 274 lobe sep 110 degrees. another would be for example a Tight Lash Comp 238 @ .050 268 running duration 110 lobe sep. These are examples only and are in the neighborhood of 2000 to 6000+ rpms. Notice the numbers are somewhat higher at 50 and lower at the rated duration, and I am running these cams myself and very happy with them.

-Gary Burnette-

I talked to Crane, Isky, and Comp Cams. Now leaning towards the Comp Cams Mega Thumper. 276 intake/295 exhaust, .489 lift. Rated 2200 to 6200 rpms. There rep says it will pull well to 6500. I am thinking 6200 would be about the max I want to go on a consistant basis with cast pistions. John mummert has two cams in the same range but having trouble deciding between the Y284S and Y 280I. Rpm range on one is 2500 to 6200 and the other is 2400 to 6200. Lift on one is .460 and the other is .500. I sort of like the Comp Cams because it comes in a little sooner. Anyone out there running the Comp Cams one??

I talked to John Mummert again today and discussed the cam selection again. After kicking it arround with him, I am leaning to his Y-292S cam. It is 292 degrees with .485 lift and 108 degree lobe seperation. Mummets Y-284S and Y-280-I-11 were allso possibilities. There are more radical grinds available from other sources but I think this is about as wild as I want to go. I plan to go drag racing with it but it will see more street time than strip time. John also said he hopes to have heads going out sometime in March. This cam is a little more radical than my current Crane so I hope to get more horesepower out of it, but not so radical as to be difficult to drive on the street.

I have and will be getting recomendations from dealers. I have also always thought it was a good idea to see what other people are using and plug that info into my decision making process. The Crane cam that is now in the engine was great but I fear that it may be going flat. It doesn't seem nearly as sharp as it used to. Also technology has gotten much better. The Crane was rated up to 6000 RPM but would easily go 6500 and I have had it to 7000 a couple of times. The tone of a Y-Block sure changes at those kind of rev's!. I am thinking a 6200 to 6500 RPM max would be prudent with the basicly stock bottom end. I am thinking with Mummerts heads and the right cam I will be more than  pleased with the improvement in performance. The plan is to see what kind of times I can turn and go from there. If I am not satisfied and want more I can always go with the Mummert intake and a large single 4 barrel and see how much better it actualy is.

Checked the Competition Cams website and they don't show a listing for  the Y-Block. Still curious as to what others are running.

Here I go again.  I've said this for years.  Call your favorite cam grinder's tech service, and carefully and honestly tell him all the facts he asks for.  Car weight, gearing, engine size, speed equipment, rpm range, and what you expect from the car.  Then let him suggest the cam grind.  He is in the business of selling cams, and he wants you to be happy with it.  Try this with other grinders if you like.  If you give each of them the same information, I'll bet they will all suggest very similar grinds.

John - "The Hoosier Hurricane"