hey guys, well ive got a 460 in my 75 that i had built by our local machine shop and it has quite a bit of power but i expect a little more out of a 460 than this. Its a D1VE block, D3VE heads, which had the exhast humps ground.R.V. cam. Its .30 over, aluminum flat top pistion, a CJ intake, along with a 750 edelbrock. Ive got stock exhaust manifolds on it running thru 40 series flowmasters. I have timing set to 12 degrees, its got the zero degree timing set. I have messed with the timing and it seems to run best where its at rite now. So guys any ideas on how i can get more power outa this thing without doing anything too major. Im thinking about having the heads and intake port matched and maybe a different cam, but what do you guys think???

 

Headers. Now.

Brad

 

really headers will make that big of a difference???

 

Well I agree with the headers. They will help a lot with letting the engine breath. You have a CJ intake with large ports and a set D3VE's have small ports. Best bet is to gasket match both ports to increase the flow. Then I can bet you will see a huge difference in the power output. Now the other question, what size valves do you have? The stock valves will limit you a ton as well. With that in mind the CJ intake won't do anything for you. The major choke point will be the stock D3 valves.

 

It is not worth all the work to port match your heads to the CJ intake. I have run them mismatched then matched and there is little to no difference. It takes ALOT of grinding to do it also. Did you use gaskets for the CJ intake? If not you will have a internal vacume leak.

 

ok i will think about headers next, How should i go about gasket matching the intake and heads?As far as i know i just have stock size valves, is it a big thing to put bigger valves in? CAn i just pull my heads and slide in bigger valves??? So there are special gaskets for the CJ intake, or do i need to make these by sizing them myself? So could the internal vacume leak you say i have be costing me power to???

 

As Greenhighboy put it best... it isn't worth your time port matching the intake and heads. There is a lot of material that needs to be removed to make them match. I would suggest changing the intake all together. Look at the classifieds here to find one or check some auction sites. The valves would require a bit of machining to enlarge the valve seats. Not to mention a few hundred dollars in parts and labor. Vacum leaks will make your engine run like poo. It will idle badly and stall alot to point out a few things.

I am curious to know what made you decide to go with the combination of parts? It seems like the parts are pieces that were slapped together with no thought by the machine shop for what you wanted to do. Before you buy the headers call a few intake companies and get their opinion on what would be best for your engine specs. We can all give you our thoughts but it does no good for you since we don't know anything about your budget and so on. With that said.... stop any buying of parts and get your combinations right then move on to improving the little things.

 

so your telling me that the CJ intake will do me no good even if i match the gaskets to the ports. The engine isnt running poorly like i have any vacume leaks or anything, it runs great i just feel like it should have more power, its almost like it lags quite a bit.

 

What camshaft are you using? Did the machine shop "Zero Deck" the block? Did the shop shave anything off the D3's? What distributor are you using? Rather than grinding on the CJ intake consider a Edelbrock performer with a gasket match. I am building a similiar engine for a 66 F100 SWB and expect at least 400hp on truck manifolds!

 

75fordkid call Edelbrock, Weiand, Blue Thunder, or who ever else's tech line and talk with them before you do anything more. Greenhighboy has even written that he did the same thing you are going through. He was the one who said it wasn't worth your time. I started to see that the parts weren't matched well to begin with after reading all of the information you provided. I am suggesting before you dump money in the wrong parts get some facts from the experts who can tell you what will or wont work together. The tech line will ask you some specific information about your engine from deck height, cam type and specs, pistons, valve size and so on. Make sure you have that so you can be guided in the right direction. I am not trying to steer you in the wrong direction with claims of massive gains at the expense of your wallet and frustration.

William at this point it isn't a good idea to throw a bunch of questions that fordkid might not be able to answer or overload him with information he doesn't need about your engine. We all have god awing motors that we want to brag about. Trust me I know how much I love to talk about mine. The point of this thread is to help him find the best combo for what he has actually on his engine that can improve it or put him at ease with the power he has now.

 

fine u a set of dove head's from a 68 to 71 460 they have 75cc where your head's are 96cc i tryed this one time it does make a difference.

 

Oh brother here we go again with the DOVE heads, they ain't gonna gain you squat. as a couple of others have pointed out your running a mismatch of parts here that is killing the potential of the engine, and "RV" cam (I hate terms like that, it doesn't tell you a darn thing, and can mean basically anything but for the most part all I think about when I hear it is a cam intented for use in a motorhome, and I don't think of performance, and motorhome in the same sentence) you then put a HP manifold on that is intented for a completly different power range with ports that are killing your velocity of your air/fuel mix expecially at the low rpms the cam is intended for. you need to work on getting those 2 items closer matched before even bothering to think about headers. go look at a performer or performer rpm intake either one is gonna gain you a lot of low end seat of the pants feel.
And don't bother looking for the DOVE heads, unless you want to waste money chasing the dream performance or just want to be able to say you have DOVE heads cause it sounds impressive.

 

Monster brought up some good points. I've used the Edelbrock Performer RPM package, cam, lifters, intake, and carb with good results. What are you running for ignition???

 

I ran a motor very similair to yours for several years with a SCJ intake with mismatched ports with the small Lunati Bracketmaster cam and factory exhaust manifolds. It had enough power that I won alot of stock class truck pulls with it. Driving on the street it would burn a set of 33'' tires until you wanted to stop. My truck has a 4 speed and 4.10 gears with a posi. Your motor may be running good but if you have a 3.00 gear and an auto tranny your not gonna feel that it has much power. The WHOLE combo has to be right, not just the engine.

 

I didn't answer your question about the intake gaskets. The SCJ and CJ intakes have a different gasket because of the larger port. If you use standard gaskets with a combo of intake and heads like you have the ports won't seal around the bottom side.