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Author Topic:   which heads are best on a 350
jwracing48612
Member
posted May 01, 2004 03:50 PM
ive got a stock 350 going to run a .543/563 lift 252/260 duration wondering if 1.94 heads are better than a 305 head with 1.71 valve any help appreciated jwracing


KPLugnut
Member
posted May 01, 2004 08:00 PM
That is WAY too much cam for the small runners in a 305 head, so yes, the larger valve head would be better (but the cam is still rather large for the 1.94 valve head, too). And ya better have some stout valve springs for it, in addition to high quality valves, locks, etc.
Otherwise, you'll just float 'em at 5000rpm or so, and drop one. That is, if you even have enough guide-to-retainer clearance in the first place. And rocker geometry is going to be critical as well.

JMHO...

KP


jwracing48612
Member
posted May 01, 2004 09:28 PM
i talked to competition products and thats what they told me to run with 600 lift drop in springs this combo wont work what cam would u run in a stock 350 with 305 heads


racer17j
Member
posted May 01, 2004 10:59 PM
unless they had some magor valve work i wouldn't run those hease the comp is better but you can't get the flow to take advantage of it i'd have the 350's milled down a bit if you want to bump compression and wouldn't run much over 530 cam. right now i'm running flat top 355 with 882 2.02 valves and run a 510 cam works pretty good thats whit a 2 brl


smayo964
Member
posted May 02, 2004 05:42 AM
Jwracing. I've run the 58cc 305 head on just about every engine I've built (305, 350, 400), all with flat tops. Heads were blue printed, ported, etc., and worked well with cams anywhere up to .535 lift. I've run the combinations in my street stock and my mods up to 7,200rpm. I was restricted in lift due valve length and with valve size, but had plenty of power band. Going to have the heades cut for larger valves later to see what else I can get out of them.


jwracing48612
Member
posted May 04, 2004 10:42 AM
thanks smayo thats what i was told to they said the big lift will keep tires from spinning so much coming off and still have good power all the way down i think i will run the cam they told me which is real close to a midwest #6 thanks again jwracing


ss99
Member
posted May 04, 2004 04:36 PM
jwracing,

You seem pretty convinced on sticking with that cam. If I were you, I would seriously considering listing to KPlugnut's advice. That cam is way too much. Are you running a 4bbl or 2bbl carb? If it's a 2bbl, that cam will be dead coming off the corners.

Just my honest .02

ss99

waltonjr1
Member
posted May 05, 2004 02:17 PM
You will never feed that cam enough air with that much lift. Get you a cam around .500 with around 240 on duration. The trick is to keep the valve open longer to let as much air as possible in the head. Duration is more important than lift on air restricted motors.



jwht2315
Member
posted May 06, 2004 11:02 AM
We use a setup like yours and we found that the 501 Magnum Comp Cam works the best. Might want to consider that.


jwracing48612
Member
posted May 08, 2004 04:46 PM
thanks for the help on this subject comp products told me it would help with wheel spin coming off but i think i will go to the track and ask some of them what there running and go for there thanks again jwracing


racer17j
Member
posted May 09, 2004 09:15 AM
the reason it will help with wheels spin is lack of torque last week i had no problem with wheel spin i also got pulled by everybody and there brother because i had no bottom end use your foot to control wheels spin not your motor


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