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Old 11-03-2012, 09:34 AM
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Originally Posted by rube'68'03 View Post
You're not talking about porting the bowels are you?
I am talking about porting the whole intake and exhaust ports including the bowls.
Bowl hogging is just one step in the process. These heads need more than just a "stage 1" "pocket port"
"bowl port" job. The meat and potatoes flow gains are deep in the port. And it gets time/labour intenstive.
(when you are paying for the time...)

If you want a powerfull 307 you want to fully port the 416 heads as well as get the larger 1.94" intake valve so the heads flow more air than stock.

Cam choice depends on the desired rpm range, and power/torque curve desired.
Choice must be tempered to driving style, idle quality, gear ratio,vehicle weight,
purpose, trans torque converter stall speed. A cam cannot be a big race cam and a small mild cam at the same time.

Eg if you don;t want a race motor, don't use a huge racey cam.
283's 302's 305's and 307's are easy to over cam.

deck height: bring the piston to TDC and measure how far below the deck the top of the piston is, Uisng feeler gauges, a depth mic, etc. You are looking for .025" or less. Ya it matters. (to calc the compression ratio)

If you take care of the details this 307 will turn out very well.

Google search for camshaft selection and technical camshaft terms like lobe lift, duration @.050" lobe separation, valve lift, rocker arm ratio etc etc etc. many of the camshaft manufactureres have a tech section on their sites.
Crane, Isky <Comp, Lunati, Howards,, etc etc

More SBC high performance build knowledge including head porting Search for books by David Vizard on Amazon,,, local library etc.
google search for ported 305 head,, ported 416 head etc

Last edited by F-BIRD'88; 11-03-2012 at 09:49 AM.
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