Rebuilding my 410

[JimNolan]

Hello guys,
   As some of you know I've been fighting an oil leak and it's going to get fixed in the next 30 days. My machinist owns a garage and he's going to do it for me. While I've got it out I'm putting .038 Edelbrock head gaskets on it (I found a small amount of antifreeze in the oil leak) and I'm going to put the original rocker stands and drip trays on it. I'm sticking with the 1.76 rockers (the rockers and shafts are new). I'm also getting rid of the windage tray ( About .200" of gasket material to use it). The new cam I'm putting in is the 268H comp cam. That will peak my horsepower around 4500 rpm instead of 5000 rpm and give me more torque and HP to 4500rpm. (it'll also give me more confidence in the original rocker configuration).
MY QUESTION IS THIS: Comp Cams says the 268H cam will work good with 9.25 Static Compression. Has anyone used this cam with only 9.25 CR and what was your experience?

[Joe-JDC]

I used a 268H in my 408M(351M-400crank-.030) engine, and it worked excellent.  Had a little lope, had enough vacuum for brakes, etc., and really woke up with headers and 4v.  Would pull strong to 6000, so I don't think you will be disappointed.  Joe-JDC

[My427stang]

It'll work fine, very slightly on the low side of compression but should be a great all around driver

Are you sure you are only 9.25:1 though?  It's not easy to get a 410 down that low unless it's got a lot of deck clearance

[JimNolan]

It'll work fine, very slightly on the low side of compression but should be a great all around driver

Are you sure you are only 9.25:1 though?  It's not easy to get a 410 down that low unless it's got a lot of deck clearance

Russ,
The Edelbrock heads has 72cc's and the gasket is .038. The deck has been cleaned up and I was miking .023-.024 to top of block when assembled. The piston is a -15 cc dish 1.66" comp. height piston. The quench is going to be about .061-.062. I'll live with that. The big thing I'm worried about is the carb. I love that 750 Holley. It has a great choke for cold weather, starts, idles and runs great. I hate letting it go. Do you think it'd be too much for that engine? When I work it up on the computer program it just gains me about 2-3HP over a 670 Avenger. Thanks Russ.

[machoneman]

Keep it then. It'll be fine.

[cjshaker]

Yep, I'd keep the 750. It's perfect on my mild built 390. About the best all-around carb for any mild 390/427/428.

[JimNolan]

Thanks guys,
    The 750 has won a place in my heart anyway. It's the first carb that all I did was set the choke idle adjust and that was it. Nice looking spark plugs, good idle, plenty of vacuum, secondary spring was correct for my cars weight, no bog at low rpm or secondary transition, etc. And, it was still pulling hard at the end of the quarter mile. That 410 makes a beautiful engine for my 57 Fairlane, if it just weren't for the damned oil leak, can't stand that. 

[My427stang]

I think the carb is fine

Although I would like to see a little tighter quench, and unless you measured the chambers on your heads, I'd assume they are greater than 72 cc, so you could likely cut the deck a little and still be at 9.25 or so (Although I am not recommending assuming, I'd measure them)

[JimNolan]

I think the carb is fine

Although I would like to see a little tighter quench, and unless you measured the chambers on your heads, I'd assume they are greater than 72 cc, so you could likely cut the deck a little and still be at 9.25 or so (Although I am not recommending assuming, I'd measure them)

Russ, Believe it or not I sure did CC the Edelbrock heads. The only spark plug I had at the time was a lawn mower plug that didn't reach that far but it was 72cc. I only measured one chamber though. I figured if it was made on a CNC all of them would be equal. With this setup I'll be getting 336 ci out of it and going from a 7.5 DCR to a 7.7 DCR. This combination gives me a lot more torque and a little more horsepower up to 4500 rpm. I don't drag race my car often so I can't see missing the 4750 up rpm anyways. I'd rather see the .061 quench than keep the head gaskets I'm running now.   

[My427stang]

Sounds logical to me!