r37ribution
Well-Known Member
- Joined
- October 7, 2004
- Messages
- 705
- Reaction score
- 2
- City, State
- Ypsi/MI Y town! whoot whooot!!!
- Year, Model & Trim Level
- 1996 "Sport" XLT 4.0L OHV
I recently recieved a set of heads from Alabama Cylinder Heads. I got my motor pull out and noticed that the exhaust ports on my stock 1996 4.0 heads are much larger than those which are on the new Alabama stock replacement heads. The heads that BBK and JBA sell for a 95-98 4.0 have 1 5/8" primaries and their newer heads as well as Pacesetter and Hedman for 98+ are 1 1/2" primaries. So I'm guessing that Alabama ships a generic head for the 96-01 Xs with the smaller exhaust ports similar to that of the 98TM.
I have heard that there smaller ports in the 98TM heads causing the gases to leave the heads faster and thus heat up the cats more quickly making them more efficient. I thought they were referring to the exhaust valve size not the exhaust port for the headers.
So my question is, ignoring the cats which I don't have, which head performs better? I would assume the larger exhaust port, it looks much bigger. I have a set of BBKs with the 1 5/8" primaries and want what would work best with them.
95TM vs Alabama:
95TM:
Alabama:
I have heard that there smaller ports in the 98TM heads causing the gases to leave the heads faster and thus heat up the cats more quickly making them more efficient. I thought they were referring to the exhaust valve size not the exhaust port for the headers.
So my question is, ignoring the cats which I don't have, which head performs better? I would assume the larger exhaust port, it looks much bigger. I have a set of BBKs with the 1 5/8" primaries and want what would work best with them.
95TM vs Alabama:
95TM:
Alabama: