bad camshafts on 305's,,?

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Ilike55s

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I just bought a real nice 82 Silverado that developed 3 flat exhaust cam lobes before quick could get ready,,Oil level was good and pressure gauge is still running 25# at idle and 40 when reved up,,,no knocks except for all the popping back at the carb. I did a compression check and all the cylinders were 105 to 120.
Now,,several people are telling me the 305's were notorius for flat camshafts,,,, I've decided to tear down for new camshaft and prolly new rings as well, but now want to know if I should scrap this 305 and maybe go for a 350...OR,,I know where a 1969 327 is setting in a friends garage that I can buy fairly reasonable except have to find out IF the 327 heads are tapped for accessory bolt holes,,,,???
305 or 327,,??
 

Frankenchevy

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In your truck 305<327<350
 

shiftpro

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The 305 cams are in fact flat, from factory. The heads do not supply flow or compression, the engine cubes are mini cubes, and the valves barley open so yeah, factory cams are kinda flat on the best days.
I would go with a 350 or BB.
 

Old77

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Not sure why this was posted in the Introduction section but I've moved it for you so you get better exposure.
 

yevgenievich

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Over time running random oils does cause flat lobes on flat tappet cams. Not much reason on staying with 305 if tearing it fully down.
 

C10MixMaster

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Not a big fan of the 305 however if the cams all thats wrong with it . you can change a cam in the truck. All sbc flat tappet cams are known for going flat and modern zinc free oils do not help.. Proper break in procedures are critical you can kill a cam in the first 20 minutes. If your doing a full rebuild, 350 all the way, makes more torque than the 305 or 327
 

78C10BigTen

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Not sure why this was posted in the Introduction section but I've moved it for you so you get better exposure.
Seems to be a rash of this lately
 

78C10BigTen

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Tell me about it. I don’t get it unless it’s just pure laziness and posting in the first place you see
Need to learn GMSB ettiquette
 

Dave 84

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A super tired 454 for 400 dallars will out perform that 305 like crazy! engines are everywhere this is just a small example!
 

Rusty Nail

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I always figured the primary cause of a "flat cam" lobe was the ******* turning the wrench. :shrug:

P.s. I vote 327. '69 heads prolly got the holes..
 

TPISly-C10

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Back in da days early 305 got this common problem of cam worn out fast ;)
 

halljam70

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Bought my 86 with a flat cam in its "350". Motor was a rebuilt 305. I replaced the cam and lifters (cheap 204 / 214 flat tappet cam). Didn't replace valve springs, and only ran shell diesel oil in it. Results, 25K miles later, it ate a cam again. This time #4 intake (at least). Found a 94 TBI 350 pickup motor, will replace its flat tappet cam with a factory 94 Z28 LT1 cam, hydraulit roller lifters, etc, just to ensure it doesn't eat another cam.
 

idahovette

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Not a big fan of the 305 however if the cams all thats wrong with it . you can change a cam in the truck. All sbc flat tappet cams are known for going flat and modern zinc free oils do not help.. Proper break in procedures are critical you can kill a cam in the first 20 minutes. If your doing a full rebuild, 350 all the way, makes more torque than the 305 or 327
If you just do a cam what do you do about all the metal from the cam that's left in it? Lots of nooks and crannies .
 

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