A Few Q's
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From: columbia
A Few Q's
Just want to make sure but, If I put a Comp cams 268H in my 400 will I need a higher compression ratio than stock? also, will a holley 600 be large enough for it? I herd that A 650 would be better is this true? Here is My engine build plan what do you guys think? stock 1978 400 with 268H cam Holley 600 carb Edelbrock performer400 intake Headers, mallory unilite distributer, Heads cleaned up a (stock) Forged speed pro pistons, 3angle valve job. would I be able to use the stock connecting rods? Is there anything that I left out? has any one done a similar buildup?are there any likes dislikes with this setup? Thanx for any info
Last edited by 78custom; Mar 31, 2004 at 12:32 PM.
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From: Eastern Pa
I just got mine running a few days ago. Similar to you but I used the Crane 272-2 powermax which is a little more aggressive and I had some concerns as it is recommended for 8.7:1cr or higher which is right where i'm at. Was also border line on the stock torque converter. I have the Edelborck 600 and performer manifold, headers and roller rockers and a port a polish job. So far everything seems to work well together. I haven't taken it up over about 4200 yet and it pulls real well even down low. In fact I have to be carefoul not to push the gas too hard when taking off or it easily spins my 33's with 350 gears.
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From: Delaware
You don't need forged pistons. You should go with Badger Flattop pistons, and take 0.010 off the heads to get 9.0:1 CR. I prefer an Edelbrock carb (600 CFM) to a Holley, and a 265DEH to a 268H.
Yes, you can use you stock connecting rods.
If you go with what you listed it will run good, but get the CR up to near 9:1. Use the Badger pistons even if you don't mill the heads. It will run better.
Yes, you can use you stock connecting rods.
If you go with what you listed it will run good, but get the CR up to near 9:1. Use the Badger pistons even if you don't mill the heads. It will run better.
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From: columbia
I was going to use the speed pro pistons because they were like 300.00 and specific for the 400 I'll look into the Badger pistons can I use them with stock heads?
I'll look into the Badger pistons. If I use them can I still use the stock heads? I missinformed you guys it's a 78 351m that I'm turning into a 400 are the heads the same? Hope this doesn't change the information on your responses. Thanx for the info! keep it comin!
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I'll look into the Badger pistons. If I use them can I still use the stock heads? I missinformed you guys it's a 78 351m that I'm turning into a 400 are the heads the same? Hope this doesn't change the information on your responses. Thanx for the info! keep it comin!
-EDIT- You can edit your own posts for up to an hour after you make them rather than making a new post. -Admin
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From: Delaware
With 351C-4V closed chamber heads (62.8cc), and flattop pistons(3cc) and 4.0 Bore your compression ratio will be 10.35:1 in a 400 motor. If you use a cam with an Intake Valve Closing (IVC) of 68 degrees ABDC (seat to seat) your Dynamic Compression Ratio (DCR) will be 8.0:1. This motor will run fine on 93 Octane.
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From: columbia
So I can use this Cam and stock heads. kool!! that's what I like to hear I didn't want to spend time and money looking for heads that will work with My combo(not now anyways). But what about the Carb? Is it large enough?
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From: Delaware
A 600 CFM carb is fine. The gas mileage should be in the 8-10 MPG range. The 268H cam has 48 degrees overlap, and the 265DEH has 50 degrees overlap.
Don't oversize the carb. It will hurt you in driveability and gas mileage. The smaller the primary venturi the better.
Don't oversize the carb. It will hurt you in driveability and gas mileage. The smaller the primary venturi the better.
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From: columbia
I'm not worried about the Gas milege the truck is paid for so getting gas will be cheaper than car payments. swee I think I havbe all that I need Now all I got to do is start on the engine. Thanx for the info.
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From: Delaware
The ports of a 4V head are much larger than a 2V head. You can't use a 2V intake manifold with a 4V head and vise-versa. Since there is no such thing as a 4V intake manifold for a 351M/400 motor, you have to use a 351C-4V intake manifold and adapter plates.
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From: East Bend, Carolina, U.S
All 351M and 400 heads are the basically the same as the 351C 2V heads except that the 351C 2V heads will out flow them. Ford never installed a 4v carburetor and intake on a truck with a 351M or 400 that I know of.
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From: columbia
Danlee, Actually they do make a 4v Intake for the 400/351m It's a Edelbrock Performer 400 Look in the newest Jegs or Summit in the Edelbrock they list in the intake section. It's a 4v intake all aluminum and cost 186.99 with only the manifold.