questions about RR
Racer
Joined: Feb 2002
Posts: 293
Likes: 0
From: Benoni Gauteng
A while ago i put them on my dads 90, and they gave a nice gain, can't remember what the figures where but i know it was quite good. by the way we also had to change the guide plates as the standard ones arn't hard enough.
Burning Brakes
Joined: Jun 2003
Posts: 1,229
Likes: 1
I'm also curious about the 1.6 and 1.7 RR, I keep earring about guys with LT4's and LT1's installing them and getting like 15 to 20 hp gains.
What about us L98 guys? would a 1.6 or 1.7 RR really be beneficial?
Anyone done this before with an L98 with actual numbers?
What about us L98 guys? would a 1.6 or 1.7 RR really be beneficial?
Anyone done this before with an L98 with actual numbers?
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
On an L98 you can expect to see 10-15chp gain from RRs.
On '85 & '86 L98s it is prefered to install 1.5:1 on the exhaust and 1.6:1 on the intake to avoid rough idle. In installed Comp Cams ProMagnum 1.6:1 RRs on both int & exh with my Al heads and idle is even smoother than when bone stock.
On Al headed L98s it is necessary to shorten the valve cover drip tabs and narrow the bolt towers to clear the ProMag RRs.
On '85 & '86 L98s it is prefered to install 1.5:1 on the exhaust and 1.6:1 on the intake to avoid rough idle. In installed Comp Cams ProMagnum 1.6:1 RRs on both int & exh with my Al heads and idle is even smoother than when bone stock.
On Al headed L98s it is necessary to shorten the valve cover drip tabs and narrow the bolt towers to clear the ProMag RRs.
Team Owner
Joined: Sep 2001
Posts: 62,127
Likes: 1,727
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
The last time I looked at prices on 1.6 they were about 250-275 for a set.
They are worth the expense on any C4. 1.7s will require stiffer springs, so that will depend on a particular combination on the L98.
They are worth the expense on any C4. 1.7s will require stiffer springs, so that will depend on a particular combination on the L98.
