I’m putting the 400 back together for the wife’s truck. Trickflow PowerPort heads, Howard’s rattler bud roller cam, scorpion rockers, trick flow pushrods, custom ractec pistons. All machine work done and pretty much resembled. I’m down to pushrod length checking. I came up with 9.0” on the intake and 9.150” on the exhaust. I really expected intake and exhaust to be the same length. I called trickflow and the guy I talked to was thinking the same but did say “I could be wrong”. anyone used these heads and could shed some light on this? I made sure I was on base circle and the cam was degreed to within .5 degree of center line and .3 degrees on the duration

 

First thing I would do is mark the dizzy base with a line pointing at each cap electrode. Mark them 1-3-7-2-6-5-4-8 in order. Remove the top of the dizzy cap, turn engine over to cylinder 1 TDC and zeroed degrees on the harmonic balancer. Mark the Dizzy's rotor where it matches the mark on the Dizzy's base for cylinder one. Now as we go thru the firing order to determine pushrod length, we have a reference to stay on the base circle of the cam IF the cam was installed correctly. Now measure the distance between the rocker arm cup and the lifter cup (with the rocker tip centered), than add .030"-.040" for lifter collapse. Also add 1/8 turn to your final adjustments to take into account for the alloy head expansion. Next turn engine over and line up the dizzy and rotor marks for cylinder 3 and measure just as you did for cylinder 1. Repeat this process for all cylinders and compare. They all should be fairly close if the cam was installed correctly and the valve stem heights are the same. If all the intakes are the same and all the exhaust are the same I wouldn't worry to much as long as there is a good centered sweep on the valve stem. The sweep on the valve stem is more important than the lengths being the same.

 

Here We Go -

 

I think I figured out my question. The exhaust is raised 0.1” so that with the cam manufacturers suggestion of .050” preload im right there.

 

The exhaust valve stems or the exhaust ports? The TFS 195's have .100 raised exhaust ports that matches the exhaust gaskets, all the valve stem heights should be the same.

 

same thing happend to me with aussie heads. Exhaust and intake were 2 different lenght. The machine shop i went to made and average of intake pushrods lenght and exhaust too. Because i arrive there with 16 different lenght and then asking me if i was an engine builder lol