461 Double hump question
Thread Starter
Drifting
Joined: Jul 2000
Posts: 1,266
Likes: 0
From: Allen, TX, USA
461 Double hump question
These heads do not have accessory bolt holes in them, but is it
true that you can't drill and tap the head for an accessory bolt?
I've heard that you can, but also have seen others say you can't.
Maybe it's one of the other casting numbers that you can't do this to.
Anyone know?
Burning Brakes
Joined: Dec 2000
Posts: 1,183
Likes: 2
From: Des Moines Iowa
Re: 461 Double hump question (adam)
It is my understanding that while you 'can' drill and tap these heads for the accessory bolt holes, it is NOT ADVISED, since the heads likely don't have the cast reinforcements at these loccations, which are present in heads originally cast with the accessory bolt holes.
Kind of like you can drill out and tap the Vortec heads for the old intake manifold, but this method is not recommended, and probably not very reliable.
Kind of like you can drill out and tap the Vortec heads for the old intake manifold, but this method is not recommended, and probably not very reliable.
Le Mans Master
Joined: Sep 2000
Posts: 5,635
Likes: 4
From: Orlando Floriduh
Re: 461 Double hump question (adam)
461's are early 60's 327 heads (AKA fuelie heads) You should be able to sell them very easy for a good price and then buy something better suite for your needs. :blueangel:
Pro
Joined: Jan 2002
Posts: 534
Likes: 0
From: FL
Re: 461 Double hump question (adam)
I know nothing about these particular heads, but...
Seems kind of common-sensical.
1. Check to see if you're about to drill into anything obvious.
2. Assuming the answer to 1 is "nope", then drill and tap. Go only as deep as you need to.
3. If your drill intruded into the water jacket, seal the bolt with thread sealer (I use RTV) when you install it.
-Noel
Seems kind of common-sensical.
1. Check to see if you're about to drill into anything obvious.
2. Assuming the answer to 1 is "nope", then drill and tap. Go only as deep as you need to.
3. If your drill intruded into the water jacket, seal the bolt with thread sealer (I use RTV) when you install it.
-Noel
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: 461 Double hump question (adam)
It has been a very common thing to drill and tap accesory holes in those pre 70 heads. Older shops started that 30 + years ago.
