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burnin oil · 08-15-2021, 08:55 AM

Most the off the shelf cams for SBC come with 4 degrees advance ground into them. Been like that for years. Not a big deal since most people buy a cam that's to big. Reading lift depends on the cam manufacturer and lifter type. 50 readings became the standard for comparing cams but the ramps could be doing anything before that. Depending on how old that rebuild is it may have a true cam grind. As for cam choice I would keep it in the RV cam range and you will be happy. 283s are small and that short stroke makes them have a higher power band than the cam is rated. It doesn't take much to need to go to deep rear gears! Back before vortec motors I knew a guy that built a 283 with RV style cam and large valve 305HO heads. Good power and was knocking down 20mpg in a square body daily driver. Large valve heads are iffy on a 283 since the valves are really close to the cylinder walls. Valve shrouding can be an issue and cause a loss in power. Worth checking while the motor is on the stand. Depending on usage I would consider upgrading the heads. Power pack heads were good back in the day but there are alot better now. Other than the intake cost I think vortecs would be a good match for a 283. Plenty of flow with good velocity without being over sized for a smaller SBC. Would love to hear others opinions on this.

08-15-2021, 08:55 AM	#7
burnin oil Registered User Join Date: Jan 2013 Location: Eastern TN Posts: 1,921	Re: 283ci and cam timing wheel Most the off the shelf cams for SBC come with 4 degrees advance ground into them. Been like that for years. Not a big deal since most people buy a cam that's to big. Reading lift depends on the cam manufacturer and lifter type. 50 readings became the standard for comparing cams but the ramps could be doing anything before that. Depending on how old that rebuild is it may have a true cam grind. As for cam choice I would keep it in the RV cam range and you will be happy. 283s are small and that short stroke makes them have a higher power band than the cam is rated. It doesn't take much to need to go to deep rear gears! Back before vortec motors I knew a guy that built a 283 with RV style cam and large valve 305HO heads. Good power and was knocking down 20mpg in a square body daily driver. Large valve heads are iffy on a 283 since the valves are really close to the cylinder walls. Valve shrouding can be an issue and cause a loss in power. Worth checking while the motor is on the stand. Depending on usage I would consider upgrading the heads. Power pack heads were good back in the day but there are alot better now. Other than the intake cost I think vortecs would be a good match for a 283. Plenty of flow with good velocity without being over sized for a smaller SBC. Would love to hear others opinions on this.