here are some pics of my intake base (siamesed) plenum and heads.

 

the head was matched to a fel-pro gasket

 

the plenum sides and intake again

 

plenum EGR walls

 

clean head

 

DAMN NICE!! DAAAAAAAAAMN NICE!

 

Can I have it?

 

Why siamese the plenum openings if you're using the stock runners? Now you have a nice flat surface for the air to smack into. Otherwise it looks good.

 

well i'm planning on getting new runners or siamesing the stock runners but we'll see. plus just gets some more volume in the plenum every little bit helps
also stock there is that ridge hiding the other runner from a good amount of air that then has to flow around the wall.

i was gonna siamese the runner part that the actual runners are welded to but decided against it.

i forgot to mention that the intake base is siamesed 4 inches deep. i will probably go more when i get a 350, 383, or 400 (haven't decided yet) and a bigger cam

oh and here's my sig and the times in there don't reflect the new porting but i should have dyno numbers in about 2 weeks
Andrew

 

very nice, you went way deep on the base, I just got Rob Rabines old set up with the SLP runners(not sure what his thirdgen name is but he is working on a LT1 conversion), he ported the base I would say almost a 1/4" larger diameter than stock but didnt need quite the transition as yours are either way looks good, I hope to have min all put back together this weekend, spring break is next week so I will definately have it done then.

 

let me know when you get some new dyno/track numbers!!! im going to be running the same setup in a few months, and would like to know how the siamesed manifold performs on a mildly modded 350. ive got close to the same amount of mods as you, but im not going to be porting my heads. i was also going to do the LT1 cam swap, but some people on this board have told me its not worth the work to install a cam if im going to be swapping that one in. let me know if you see an improvement

 

question. why saimes the base and plenum if the runners are not saimesed? will you still see the full gaine of all that work and are they stock runners?

 

Looks GREAT man. I bet you'll notice a big difference especially when you get the runners too. I'm gonna be doing this to my hotcammed L98. Think I'm gonna get the SLP runners too. good luck, let us know dyno #'s!!!

 

because that way each intake port can pull from both runners.
Andrew

oh and i haven't gotten any times with it yet haven't been able to go to the track. it feels stronger and i'm pretty sure i'm gonna be in the 13's

 

How long and painfull was the process of porting the plenum. I have the slp runners and edelbrock base, i'm debating if i should knock the walls out of the plenum and port out the SLP runners. Is this worth it, and cant wait to see your knew numbers,
Good Luck

 

if you get some carbide bits its not gonna take that long and you'll find other stuff to do i did the erg walls in like 20 min with a carbide bit and a drill. now that i have the die grinder it would be done in like 5.
Andrew