i have a 91 tpi in my truck with all the parts in my sig....im lookin to get some 113s but how much will i agin from them? i could do a lil self portin on them to get a lil more flow!! i just dont want to spend the money for afrs and with my motor not pullin over 5500-6000rpms i dont see why i need to get afrs....what do you all think!! thanks ryan

 

" i could do a lil self portin on them to get a lil more flow!!"

Or you could do a lot of "self portin" and get a lot more flow.

The OEM 113's don't flow any better than your 083 cast TPI head do. But they will, if you spend the time to *fully* port them.
Could also set up to 2.00" x 1.56" valves too.
Of course you could get just as much gain by just porting your cast 083 TPI heads as they have just as much power potential with equal porting. " A little portin" is not goig to cut it. But a full port job will.
The only advantage to the 113's is the D shaped exhaust port. Its very good when ported.

Apparently the newer 113's sold thru GMPP are coming thru with a good bit of valve bowl work already done which makes them flow better. But could still use a full on port job.


AFR 180's are nice but you can get this kind of flow out of fully ported 113's or 083's. Your finished port size will be just about the same too. (mid 180cc)

 

so you think i coudl do a "full port job" on some 113s ive doen some port work befor but not a hole lot, i porter the crap out of my slp runner i just finshed them a few weeks ago and also the plenum.....took tiem but i got good at it after i found the right tips to use on my dremmel....i would like to find better tips to use tho!! anyone have any pics of ported 113s? i also like the fack that the 113s have 58cc to raise comp!

 

here is a pic of CNC L98 chambers.