[64gtojoe]

I have a 64 389.Its numbers matching engine except for heads n intake. Its bored .030,Ram Air IV cam,Rollertip rockers(1.50 ratio),edlebrock carb n intake..Its a 4 speed without powersteering or brakes. The heads are from a 350 motor(#47 casting).I need some advise on what heads I should get for the best perfomance for the money.I cant afford the Edlebrocks. Should I rebuild what I have? I appreciate any info. Thanks
Joe

[shaker455]

How about getting a set of number matching 9770716 heads?

[Blackcat]

I would move to the HO heads of that day the 716 castings and have screw in studs installed.
Other wise I'd move to the later 67-70 GTO heads.
Are your replacment pistons set with the 8 eyebrows for either set of heads?

You can see pix of my HO heads on my 62 Grand Prix 421 engine buildup.

http://216.178.81.108/forums/showthr...ght=Grand+Prix

[64gtojoe]

Im consdering the 716's,But to be numbers matching the would have to be datecoded correctly. I figured if the dont match anyways, I might as well get the best combo forr the $. I bought the car this way,except for the rockers and carb. The 350 heads allso have screw in studs in them. I also have Dougs headers w/Pypes X pipe 2.5 duals. Im not sure of the pistons.
Thanks for the opinions.
Joe

[firebum]

64gtojoe,

How about a set of 092's? These heads have been maged, and rebuilt and never run. This is what they are:


UNIT TYPE YEAR DATE CODE NUMBER COMMENT

1 092 1966 D186 2092 389,421
2 092 1966 J 66 2092 389,421

NOTE: These heads were used in both the 389 and 421 engines in 1966.
The 389 HP ratings were: 290,325,333 HP with 10.50 CR.
The 421 HP ratings were: 338 & 350 HP with 10.75 CR.

I have pictures but need to figure out how to get them to show up.

Thanks,

Jim

[Ollie]

Keep the #47 heads, If you go to a numbers matching head you will also have to change the intake mainfold.
Using The #47 heads gives you the option of using any modern intake Manifold. With a chamber volume of 72 cc, on the 30 over 389 puts the cr at 9.6 right in the 9.5 cr for todays gas. the 1.96 / 1.66 valves are also close to the original valve size for a 389.

[b-man]

The '716' heads are nice for correct restorations, but they're a dog performance-wise compared to any of the later heads.

The '092' heads aren't much better than the '716' heads other than the fact that they give you the ability to use the '65 and later intakes.

I would either rebuild what you have or get a set of '67 -'70 400 big-valve heads. Larger valves can be added to the #47s for not much more than the cost of new smaller valves and you can have a street-porting job done on them. A bowl clean-up and bigger valves along with a quality valve job would net you a nice relatively inexpensive flow increase.

Leave the old 389 heads for restorations, if you want more power you really don't want them.

[64gtojoe]

Thanks for the input. Ill prob. keep the 47's.
Joe

[BruceWilkie]

I have used 68 #17 heads and 70 #11 heads with good results. The 17's on a 400 and the 11's are on my sons 64 Bonneville 389. They are not bad heads for a street car with a mild hydraulic cam. Add screw in studs and big valves to the 47's and you got essentially a #48 head (11's = 12's etc.) The best thing about using small valve heads for cores is that installing large valves allows the valve to be set where the factory intended. (Large valve heads after many years and unknown valve jobs tend to have the valves a little to recessed for optimum performance without having new seats installed which drives up cost. Large valve head cores are usually more expensive too!) The ports are the same. So yeah keep your 47's.

[64gtojoe]

Thanks for the info. My #47's already have screwin studs. Thats one reason I thought about keeping them.
Joe