New Member
Apr 23, 2014
I have a 1997 GMC K2500 Suburban with an L29 454 4WD. I am currently doing an engine build. I will be running a Competitions Cams camshaft with 0.54" intake and exhaust lift (with 1.8:1 rockers), 206 degrees intake duration at 0.050" lift, 212 degrees exhaust duration at 0.050" lift. I hope to be running Doug Thorley Tri Y Headers. I can get the Tri Y Headers from Summit for a 1995 K2500 Suburban with an L19 454 and 4WD. i was wondering if they would fit my truck with L29 heads (Summit part # DTE-388Y-C). I bought some Keith Black (Kb-202-030) hypereutectic pistons. Running a stock L29 head with 100cc chambers will put me at about 9.5:1 static compression ratio. I was wondering if you guys could suggest some intake and cylinder head upgrades. I want to run port fuel injection. I am building this engine to have low end torque. I want it to pull heavy trailers effortlessly. Any suggestions.


Feb 8, 2012
North Dallas
Since they are made for 4x4, there may be slight fitment issues, not familiar with the setup, but I can't see any issue why they wouldn't fit the actual head.
why not after market heads? thats what really kids those motors, same thing with the later model 460 fords. to meet emissions standards they make the ports so damn small.

fuck im running a small block with bigger intake and exhaust runners then that thing has.

if you want proformance on a later model 454, start with the heads.