Steve Gunn

...at moderate power levels, is there really a significant payoff? I understand about deflection at high rpms. I also understand about the needle bearing issues with stockers. I also understand a small gain can be had with roller tips.

30K miles ago, my dyno showed that my power fell off around 6k rpms at 383hp/375tq. Pretty weak for a full bolt on heads/cam combo. I have one of the first batches of yella terra's that rumor has it were too heavy on the valve side of the trunion, possibly causing float. The pushrod length was checked for correct length, geometry, etc.

Just for grins I'm replacing the yella terras with stock or something like Harlands just to see if that's where my missing horsepower was. I'll be spinning to 6800 rpms. I'm also changing the springs to 918's and 7.4 pushrods.

What's the best choice, guys???

redtail2426

iTrader: (10)

having the stockers rebuilt by harland sharp is the best thing to do in my opinion.They are very light,strong and reliable.a lot of aftermarket rockers cant compete with the light weight over the top of the valve that the stockers provide.

Blackss99

iTrader: (1)

Good info to know

sho-me speed

iTrader: (55)

What springs were you running with the Yella Terras?

heavymetals

iTrader: (3)

I am a mod junkie (there I admit it) and I am using the Comp Cams #1500 system.

This is because the only way to "dial in" the preload is with adjustables.

They have a really neat oiling system for the bearing and the roller.

Steve Gunn

mti duals

I'd like to have that, but long story short, I'm trying to just make this last another year or 2...midlife crisis damands a vette next.

mrr23

iTrader: (3)

i use the vinci/crane accelerated lift rockers. here's dyno results from the wife's car on stock tune, stock cam with 1.8 rockers. gains can be had, with the right rockers.

02silvaZ

iTrader: (12)

i would believe if you find the right ones it would definitely be worth it, the added lift definitely has to help

vettenuts

iTrader: (4)

I would simply swap the Yella Terra's you have for the newer design that is lighter. Also, there has been a lot of issues with 918's recently, I wouldn't trust them right now. Comp stated they changed vendors and were having issues then subsequently retracted the statements. I am running the Cranes but it sounds like you are trying to keep within a certain budget.

cowboysfan

properly setup for roller rocker will give you gains, YT as new rocker compared to thier old style. so that alone will improve hp. you also need to have the correct spring setup or you can get foat.

Rob

iTrader: (6)

Running the new YT's and really like them.

RGKSR

iTrader: (9)

I just got the mods done to my new L92 rockers.

I had the same cam as you (R1) in my 347. I hade 420 RWMP on a nice ECS tune.

I had 918 springs with ti retainers and on the dyno it was still pulling strong at 6500.

With the new setup (402/L92) and 650 lift, I went with the modded rockers for insurance. They really did a nice job and turn around was very fast.