Ok, as some of you may now, I am planning a mild build for my 87 SC with a 2.8, I know I am going to have to do something with the heads but I figure I will start from the top and eventually get to the heads. I know I need to do something about the bend in the lower plenum. But I was looking at my TB earlier today and I dont see much more then a little bit of a polish job. Any input on techniques for porting the TB to Upper Plenum a litttle but? Thanks.

 

when I started porting out the intake manifold on my 3.4 bird I started at the top and I gutted it as much as I could and started with a basic gasket match then gutted more then started cutting the gasket back to accomodate. When I got to the middle I started with opening up the gasket matching it to the top and then gutted it all the way to the bottom where I had to do the same process on the heads and lower intake but I also unshrouded the water jackets on the intake to the heads. Porting the 2.8 top end will still leave alot to be desired but it will make it more bearable till I have the time to make my own intake manifold.

 

Thanks, I would like to port it as much as I can without screwing up the flow in any way. I've seen other members reach around 170cfm per runner, I would like to see that maybe more, but I know I need to do something with my heads.

 

I took the throttle body off today and cleaned it up, I think I did a decent job, I wasnt going for anything to drastic, just wanted smooth out the big hump into a nice gradual slope. I may have been going crazy but throttle response seemed to have improved a little bit. Next is the plenum
Here is before and after, tell me what you think.

 

thats cleaned up nice, i like it. stil i would look at bigger throttle bodies as ours are tiny ! but for the money you cant beat it eh !

 

Yeah I really want a bigger TB, I just dont know what I am going to do about the plenum/heads.

 

https://www.thirdgen.org/forums/v6/3...hlight=porting

Heres a thread i did a while back. This has been covered a few times. Try searching and see what others have done.

 

hey, just wondered if youve refitted your throttle & noticed any differences ???
have you tackled the plenum yet ?

 

Yeah throttle response is better. I havent been able to take it out since then(fender/hood r off) so I dont know how it will perform on the road. I tried to get my plenum off but a mechanics bar and hammer couldnt budge that 21yr old gasket. I'm going to give it another shot, hopefuly with better results. Will keep you updated though.