451 went boom

Whats going to be better on this, a Performer or Perform RPM intake?
They are about the same. The performer rpm is a better manifold because it has, longer runners (taller), and bigger plenum volume (notch in the divider wall)
 
So I wont notice a difference?

I don't think the Performer intake is much if any better than a stock Thermoquad intake. If I had to buy an intake it would be the Performer RPM. Indy also makes a big dual plane but it might be too much for your particular application plus it's $200 more than the Edelbrock.

If your MH 440 still has its original TQ intake, you could try an adapter to use your AVS in keeping with the bucks down approach.

A well sorted Thermoquad would be a win win too.

Kevin
 
I was given a performer, but I can squeak out the coin and buy an RPM. I already have an 800 cfm AVS2 carb.
 
Go on their website and read how tall they are, one may interfere with being able to close the hood. Good Luck

I had an RPM on the 451. Will the RB block push it that much closer to the hood? I already have a really low air cleaner base to clear with the 400 block.
 
Go on their website and read how tall they are, one may interfere with being able to close the hood. Good Luck

If somebody gave you a Performer, go for it. Hood clearance will be a none issue. The Performer RPM will be better from upper midrange past 6000 RPM but how much time honestly do you think your combo is going to be there?

Kevin
 
If somebody gave you a Performer, go for it. Hood clearance will be a none issue. The Performer RPM will be better from upper midrange past 6000 RPM but how much time honestly do you think your combo is going to be there?

Kevin
Seeing as I keep the rev limiter set at 5500, not very often!
 
Google around for an intake manifold dyno comparison article. Hot Rod and a few others have done them. Pay particular attention to the torque figures from off idle to 3000 RPM.

You might be surprised at what you see.

Kevin
 
Important safety tip for the 440 Source heads. Less than 5k on them and the exhaust valve guides are worn out, intake a little tighter. 440 Source does NOT service the valve guides, they are a non-standard OD, and they are a soft material. Will have to machine my heads to accept standard size guides of a harder material.
 
Important safety tip for the 440 Source heads. Less than 5k on them and the exhaust valve guides are worn out, intake a little tighter. 440 Source does NOT service the valve guides, they are a non-standard OD, and they are a soft material. Will have to machine my heads to accept standard size guides of a harder material.
Hopefully there are a bunch of happy customers out there, but over time I've heard several stories of problems with the 440 Source Stealth heads regarding sloppy machining and such. Correcting the problems eats into your savings vs getting a set of brand-name heads in the first place.
 
Hopefully there are a bunch of happy customers out there, but over time I've heard several stories of problems with the 440 Source Stealth heads regarding sloppy machining and such. Correcting the problems eats into your savings vs getting a set of brand-name heads in the first place.


I have HP manifolds and needed a head with straight plug holes.
 
Hopefully there are a bunch of happy customers out there, but over time I've heard several stories of problems with the 440 Source Stealth heads regarding sloppy machining and such. Correcting the problems eats into your savings vs getting a set of brand-name heads in the first place.
There is an extensive thread about aluminum heads on big blocks, and they all need to be looked at, the Eddy's averaged $400 for the required work, while the 440Source heads were averaging $700 for the work. I slapped mine on and went, I didn't have money. They worked, the engine failed. If I'm buying another set of heads, I'm buying the TrickFlow heads. Nothing but good reviews and I followed along when they were being tested, I'm sold on their quality.
 
Last edited:
There is an extensive thread about aluminum heads on big blocks, and they all need to be looked at, the Eddy's averaged $400 for the required work, while the 440Source heads were averaging $700 for the work. I slapped mine on and went, I didn't have money. They worked, the engine failed. If I'm buying another set of heads, I'm buying the TrickFlow heads. Nothing but good reviews and I followed along when they were being tested, I'm sold on their quality.


But, they have angled spark plug holes, and cannot be run with C body HP manifolds.
 
Back
Top