J heads upgrade

If you are up for buying valves and having the porting done, get the 2.02's. It's utter horseshit to say it will kill bottom end. The issue becomes (again) low lift flow numbers. Come to think of it, as is in vogue today, if you are going to use a cam on 110 or wider LSA definitely use the bigger valve. I just ported my own heads, and I only used a 2.02 valve. I have a bowl of about 92%, and I NET a bit over .600 lift. Since I wanted to kill low lift flow (not with bad porting so I should say I wanted to control low lift flow) I ended up with a 105 LSA.

There is way more than one way to get to where you want. I can't stress how important a custom cam is. It has to be from someone who is competent to discuss low lift flow, reversion (and how to minimize it...especially and specifically at overlap) and how LSA affects, and is affected by low lift flow. Too many guys want to open up the LSA, pull the @.050 number down and use a dual pattern cam to cover their poor porting and valve decisions.

For the average guy this gets to be monotonous. Even redundant. As an engine builder, it's about relationships. GM was famous for outrageously wide LSA's and big slow ramps with long seat duration and short @ .050 times. They were pigs in the gear change and overall power was down. Emissions were possibly slightly better, and possible idle and fuel mileage were better by a BCH. What they gave up was rediculous.

Think about the system. And your goals. My cam is seat timed at 281 and has an @ .050 of 255 on a 105 LSA installed at 105. I can make it idle at 900, but I keep it a bit higher than that. If you didn't know, I could tell you it was a 284 hydraulic MoPar cam by the sound of the idle. I spent several hours on the phone with the cam guy to get on the same page. I did my own valve job, with a specific goal. Before you do anything else, figure out where you want to be with your cam. If you are going with an off the shelf Comp or similar with a 110 LSA, the bigger valve won't know the difference.

BTW, make sure the top cut on the valve job is a MINIMUM of .060 and .100 would be better, if you can get it.

My .02 cents.