Rocker arm swap

OldSalt · April 7, 2003

In my younger days, we use to change the exhaust rocker to 1.65:1 instead of 1.5:1(stock)ratio. This would greatly improve the torque without having to change the cam. Now that I have a 88' 4X4 truck with a 5.7L(stock), I was wondering if this is still an option and if so, how might it effect the computer, gas milage, ect.

I enjoy your sight and thanks in advance.

CMNTMXR81 · April 9, 2003

Yes, it still works today. Depending on how radical a jump you make will depend on whether or not an ECM update would be needed to be burned. I'f it's only one size up, I wouldn't fret.

I do not have all the mathematics with me as to overall lift gained. I have that at home.

MarkD · April 9, 2003

I changed the intake and exhaust rockers from 1.5:1 to 1.6:1 on my '97 LT1 and picked up 19 rwhp and 8 lb rwtq.

The LS1 Camaros have a stock 1.7:1 rocker in them. An upgrade to 1.85:1 is available. These same rockers sell for a 5.3, 6.0L.

americanmuscleman · April 9, 2003

This is a TBI 350 right? If so, you'll want to get "narrow-body" rocker arms for it since it has centerbolt heads. You might also have to do some trimming on the webbing on the underside of the valve cover (I had to with mine). Its really soft metal though. It cuts like butter with tin snips if you end up having to trim anything.

Your computer won't have to be altered.

The only thing I would check is if 1.6 or greater ratio rockers will increase your valve lift enough to max out your stock valve springs.