Author Topic: which heads to put on a pontiac 350?  (Read 744 times)

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Offline v8killer

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which heads to put on a pontiac 350?
« on: August 01, 2009, 06:52:44 PM »
so what's the best bang for the buck guys?

Engine is a pontiac 350 from 1972, heads are the worst ever i think pontiac ever made lol, 7H1 i believe, 7.62 compression or some such.

so what are my options if cost was an issue? the motor was rebuilt and a different cam was put in , no idea what cam i bought the car with everything in it.

heads have guide plates in them, not sure that was factory or not.

i've heard pontiac 13 or 16 heads with the bigger intake valves but wanna get more opinions on this or any other. even aftermarket heads are ok with me i'm not a purist, i'm after more power.


1979 Frankenstein Trans am

Offline Rick

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Re: which heads to put on a pontiac 350?
« Reply #1 on: August 02, 2009, 07:21:39 PM »
If the block/heads/pistons were truly from 1972, the engine should be higher than 7.6:1.  That didn't happen until 1975 when the cars were restricted to unleaded fuel only, and the SCR was dropped via the use of "chamfered" pistons.

The best answer, of course, is to go a 400 engine.  The 350 bores are too small to really utilize the head design fully.  The bore "shrouds" the valves and inhibits the flow.  The bore on the 400 is large enough that this isn't a factor so you get full advantage of the flows available into/out of ports.

Offline v8killer

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Re: which heads to put on a pontiac 350?
« Reply #2 on: August 07, 2009, 04:04:23 AM »
If the block/heads/pistons were truly from 1972, the engine should be higher than 7.6:1.  That didn't happen until 1975 when the cars were restricted to unleaded fuel only, and the SCR was dropped via the use of "chamfered" pistons.

The best answer, of course, is to go a 400 engine.  The 350 bores are too small to really utilize the head design fully.  The bore "shrouds" the valves and inhibits the flow.  The bore on the 400 is large enough that this isn't a factor so you get full advantage of the flows available into/out of ports.

don't wanna touch the bottom end right now, got enough on my plate, i wanna maximize the 350 for the least amount of money i can, if i was to touch the bottom end then i'd drop in the 95 LT1 i have sitting in my garage.

keeping that in mind, you got any suggestions?
1979 Frankenstein Trans am

Offline grenggli

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Re: which heads to put on a pontiac 350?
« Reply #3 on: August 07, 2009, 09:58:40 AM »
Do your research if you are going to put 400 heads on a 350. If memory serves me correctly, the cylinders on a 350 if not bored at least .30 thousands will not have the clearance for the valves because of the lack of a champher.  Though I would bring this up and the experts can confirm or reject this.  I know this because I have had friends try this combo.  Some with poor results and others O.K.

Greg
1981 Blk & Gold Pontiac TTA with  455 SE clone--sold
1978 Silver Pontiac TA with BB 454 (sold)
1989 Maui blue Pontiac Firebird Formula--sold
1988 Flame Red Pontiac GTA 5.0TPI 5spd T-tops-sold
1993 Burgundy Z28 Camaro LT1 Auto hardtop==sold