I recently did a rebuild on my 460 including a light port job along with port matching the intake. I also put a Comp Cams camshaft and forged speed pro pistons. My question is about my cams specs they are .514in 514ex 256in 262ex and 210in 218ex @.050 with 111deg of LS. The summit catalog said the cam is good for 1000-5000. The pistons are domed and are standard bore. I should have about 9.5:1. Anyone had experience with a similar setup? I know that I need to have a chip burned for this setup to run best because I am running speed density. But I am wondering if this cam is compatible with the compression I now have. I went to get the truck dyno'd last week and It only gave 230hp and 330lbft the timing was at 6deg and fuel presssure at 42lbs. My A/F was about 13 at 2500 and from there it went to 14+ until they cut it at 4500.

Thanks
Justin

 

I am running the largest Exteme 4x4 cam in my 9.5-1 466. I haven't noticed any problems with breathability. But then again my engine is setup slightly differently then yours. I have a carb vise EFI and mine is set up to 1970 standards with the exception of CJ size valves.

 

Thanks for the reply. Do you have any predetination problems with that compression ratio?

Thanks,
Justin

 

You shouldn't have detonation problems with that cam and that CR. You will need to run premium gas. You seriously need a chip though. You are getting way too lean. That's a good way to melt something down.

JJ

 

I am also trying to find a colder plug I am currently running an autolite 25. I am having problems finding out which plugs are colder. And I always run 91 octane. The truck has a real hard time on hot sunny days. I cant wait to get my chip burned I definitly feal that it will make a substantial difference. Justin

 

Domed pistons are notorious for causing issues in the big block. The dome tends to take away the squish/quench characteristic that the heads are known for.

Flat top and close to zero deck with your cam would work better.

My 2c.