olds 307 and 403

I currently have a Performer with a 1" open spacer and stock non adjustable rocker arms. I have both on the shelf, just need conversion studs. This is a mild 9 to 1 Olds 350 with a custom Qjet and custom 214/214 .472/.472 cam. Stock stall TH350 and 2.78 open rear. I pulls hard and I am not changing the trans or rear gears for awhile. Just wondering if it will be worth the effort. Will I feel it and show improvement in the 1/8 mile? What about 1.72 intake and stock 1.6 ratio rockers on the exhaust? Just busy putting the stock 1800ish stall TH350 back in, should now shift around 5000 rpm instead of 4000 rpm. Just keeping the board alive☺.

AZ520

I am curios as well, I have a 74 block with dish pistons and # 8 heads. I got it used and not sure what, if any cam, might have a rv or torque cam. I am having some 7a heads rebuilt for it. I was think about doing heads and intake and adding roller rockers, but leaving the cam.

olds 307 and 403

Make sure you don't have a stock cam, they are beyond useless.

slade69

I would say you will feel a benefit Performer->RPM. You should have enough cam to see the benefit. I would not go 1.72 with flat tappets and increase valvetrain stresses. If your valves are used to travel with 1,6 ratio, and you increase it, the valves have to travel beyond the old worn pattern in the guides, no good. I know it has been done though.

olds 307 and 403

Intake valves are almost brand new, exhaust valves were reground. I may use the 1.72 on the intake and buy 1.6 ratio on the exhaust. Most builders Olds seem to like less aggressive exhaust opening.

cutlassefi

I'd do the same ratio on both. More often than not, when you see someone do less lift on the exhaust it's because it flows better than optimum of 70% to the intake at that point.
But conversely pretty much all Olds exhaust ports suck so it's a crap shoot at the very least.

olds 307 and 403

I have been happy with the 350 but will have slightly less stall and keeping the craptastic gearing. Just figured I have most of the parts sitting here.

slade69

Then you should not have any problems with 1.72. With this ratio you are going a bit over 0.5" at valve, just make sure your guides/springs allow the lift increase.

olds 307 and 403

Pretty sure they will be fine with the .508" lift. What is the best method to tell where coil bind will happen?

coppercutlass

A quick gain for me was adding an x pipe.

olds 307 and 403

Already have one but thanks. If I can hit mid 9's in the 1/8 mile, I will be happy. Will probably be a winter project.