Just brought a Fast 92 to replace my ls6 which I'd diy port matched to my cnc'd 243 heads and figured I'd do the same with the Fast . Looking in the runner on the lower left 1" from the outlet there is a sizeable 1/8" step in the casting that has to be deliberate because all the other joins are relatively flush.
Is the wall there thick enough to remove that step or does it serve some purpose and should be left alone or just smoothed a little?

 

I ported my intake also. I think I kinda ported around it and if I had to go past it some I kinda blended it a lil bit around there. Be careful not to over port or u can get down into your gasket. Good luck!

 

Also the small indentions on each side are for reference to how far u can port it.

 

I can't tell how thick the plastic is at that step without separating the 2 bottom sections of the manifold. The screws are out but it isn't budging , the top popped off relatively easy . Don't want to break it so any tips here are appreciated.
This is mainly for curiosity unless someone chimes in with a good reason to or not to remove the step in the runner because it's deliberate in the casting, not a join line, and if your making claims of a higher flowing manifold why put it there unless it's beneficial in some way. I'd like to know what that is though because its not immediately obvious to me.
It looks like I'll just port match and minor tidy up because the joint lines are actually quite good otherwise.

 

If u flip the intake over u will see 2 screws that need to come out and I think there are 4 around the edge on the inside. Thin the inside runners shell will seperate from the bottom shell. Also when putting it back together put some rtv on the bottom 2 screws for a lil extra safety against leaks.

 

All screws are out and it's still tight, can see rtv in the joinr lines so won't push on unless I reallyneed to. Might try contacting Wilson/Fast to see if they can explain what this runner "feature"is all about.

 

Did u buy it used or new? Maybe they really rtv it together if it was used.

 

New but not shop fresh. I bought from a guy who never fitted it so no guarantee it hasnt een opened by him. I assume they're assembled from the factory without sny sealant?

 

Hmmm call fast.

 

"Just injection molding process.YES port it smooth"
This is the reply I got from an email to Wilson who make them for FAST

 

Yes , I just chopped them out no worries.
Looks much better now, at least to my eye anyway.
I hope this helps someone else thinking the same thing when they look down the runners of their shiny new manifold and think those things can't be right.
I searched everywhere and couldnt find a single post or any info at all.