New Heads?

[danielb927]

Hey guys,

I will be looking for some HP improvements for my Duster here soon. I don't have the space to pull the motor so I was hoping for something I can do in the car.

Here's the specs now:

360 engine (from a 75)
Stock heads I think.
Comp Cams Magnum 280H
Thermoquad carb
Stock intake mani and exhaust manifold

Also, anyone have a guess aso to what kind of HP I might be making now? And why my engine dies when I stomp on the gas?

Edit: I can take pictures of the engine because I'm really not sure about much other than that it's a 360, thermoquad, and the cam I know for sure. It looks nice but just doesn't feel like it pulls as hard as it should or could!

 

[70aarcuda]

why it dies when you stomp on gas...

check your timing and acelerator pump on the carb...

 

[rumblefish360]

260 HP.

You have a good power making cam but lack everything else to do so. The following ideas will increase power preety well and when all done together, a output of 360 HP is possible.

Headers into 2-1/2 exhaust pipe.
Mill heads for a 9.0-1 ratio min. Treat the heads to a comp. valve job.
(Lite bowl work will help.)
An aftermarket intake is prefurred, a LD340 Modded for a T-Q would be great, otherwise, the stock intake with a few T-Q spacers under it will help.

 

[danielb927]

Rumblefish, how much would an LD340 run, and could I drill out new holes for the spread bore pattern myself? Or just use a spread-bore to square-bore adapter?

Also, how much to have the heads milled? And, if i pulled a valve cover and took some pictures of the heads do you think anyone would be able to tell me if everything there is stock or not just from a picture? Like i said the previous owner didn't say anything about them, so I was just assuming they are stock.

 

[1MeanA]

Rumblefish360 is right on. You need to move more air through the engine to make more power. Improving performance without getting into an engine pull has been the goal of many including myself when I was younger. This means changing the intake, carb, headers and exhaust. A more performance orientated cam and head work would be next. I'm assuming the bottom end is in good shape. Good luck with the project.

 

[rumblefish360]

Rumblefish, how much would an LD340 run, and could I drill out new holes for the spread bore pattern myself? Or just use a spread-bore to square-bore adapter?

Also, how much to have the heads milled? And, if i pulled a valve cover and took some pictures of the heads do you think anyone would be able to tell me if everything there is stock or not just from a picture? Like i said the previous owner didn't say anything about them, so I was just assuming they are stock.

An LD340 could run between $100 and $200 bucks.
If you ever held a dremel or a die grinder which would be alot better and quicker, you could use a T-Q gasket as a template and grind the intake away yourself. The intake is drilled for both carb bolts patterns. Skip the adaprter unless you grind it open as large as the T-Q opening on the squarebore side.
MoPar used to sell 1/4 T-Q spacers.

On head milling, that exact info is an unknown to me since you yourself have to measure how far down the piston is and how many cc's the head chamber is. As far as a stock head or not, no one would be able to tell the difference in a stock spring and most other single springs be it performance or stock replacements.

On how much to remove from the head, unless someone has been there and done that or knows your exact particulars...Like, is the head stock for that engine or has it been replaced with another stock head?

Perhaps Moper or BJRracing would know for sure. I just do want to say take off .060 and your good.

 

[danielb927]

Bump to say thanks for the advice, I think I had missed a couple of responses. I might get a new intake, but have decided not to spend too much on this engine. I have dreams of a 440 Big-block in this thing (I know it will be a hell of a project) so I'm going to start saving up for a year or two to get that done. Hoping for a budget in the 6-8k range. Will start a restoration thread when I find a block to get going! Hopefully I'll be taking a welding class which should help with the headers and such.