Ok setup is a 408 ls1 with trickflow heads. Ls7 lifters yella terra rockers comp 251 270 .638 .596 PAC 1208 springs with 1.79 installed height. Car is making great power. Car peaks at 6850 no matter what we do. I have spent over 3000 dollars trying to chase this issue but now I'm fed up. Put a stock rocker on it with trunnion upgrade didn't work put thicker pushrods on it didn't work change springs and shim them didn't work. Change cam to bullet grind didn't work. Do y'all think the ls7 lifter can't keep up with the amont of spring pressure I have in it. Please input on this.when it peaks it falls off like a rock

 

Put a mast intake on it same thing also.

 

And I'm dynoing on slicks also

 

Is it still pulling at 6850 or is it starting to level off?

 

Falling off bad and everything is brand new

 

here is the dyno sheet

 

What's your fuel system setup? What size injectors? What fuel pump? Who's tuning it?

What's the air/fuel ratio get to at those RPMs?

 

Would not be he first time I have seen that happen with stock lifters. We could not keep a stock LS6 cam stable with HS 1.8RR without going to a short travel lifter. PAC-LFT106-LS.

 

this is untuned because all we did was changed cams. walbaro 255 pump with a fast 60 lb injectors 12.9 to 13.0 afr with c16 in the tank

 

the other cam was tuned perfect

 

What kind of lobes was the old cam using compared to the new one?

What kind of valves? What rpms are you aiming for?

 

7500 is what i am aiming for the lobes on the comp cam was very aggressive lobes and and the new cam from bullet is on not so aggressive lobes. i have trickflow heads with ferrea valves 2.100

 

not just 7500 i just want it to curve and not hit a wall

 

What intake/tb are you running?

EDIT: just reread your second post.

 

How much power is it putting down before it falls off?

 

Super vic port matched with accufab 4150 and it made 548 at 6850 then fall off

 

Thanks for all you guys help

 

After speaking with alot of people they saying ls7 is like 75 percent of my problem

 

Like I said take a look at the lifters I posted. Those will get you moving.

 

Ok turbo buick6 lifters is on the way