At What RPM Do You Shift Your LT1 Cammed 305? - Third Generation F-Body Message Boards

Max · 12-30-2006, 11:02 AM

At what RPM did these cams peak in a 350 and at what RPM do they start to fall off in a 305? What is your prefered shift point for maximum acceleration?

ShiftyCapone · 12-31-2006, 11:17 AM

The stock LT1 f-body motors made peak power (as advertised by GM) at 5800 rpm. Using a set of vortec heads or a quality aftermarket head would allow you to duplicate that shift point. However, using stock swirl port heads will keep the power band lower with ported castings being slightly higher. A lot depends on the heads you chose.

In most cases an LT1 cam'd 305's will shift around 5800 to 6k rpm.

Max · 12-31-2006, 12:25 PM

Thanks Shifty. I'm using stock (un-ported) 081 heads from an LB9. You can find my list of mods in my sig. The weak link right now is the valvesprings. I need some well matched springs so I can effectively run the engine up higher. Have you heard of anyone using OE LS1 or LS6 valve spring (1.29" OD) in stock 081 heads. I'm thinking they would be just a little too big to fit.

6000 RPM sounds about right for maximum accel. I'd like to be able to safely rev higher without damaging the engine. Any guesses as to what the max RPM of a stock LO3 lower end might be?

sammyrocker5150 · 01-04-2007, 11:20 PM

with my 92 rs stock 305 and 5 speed, i shift at like 4400 cuz after that it pretty much drops off the chart.

vorgath · 01-06-2007, 01:16 PM

305 shifting at 5800 rpm ? Waow