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ford 302 carb bolt pattern doesnt match intake bolts???


7MGFORCE

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okay heres the situation i have a ford mustang 5.0 302 engine. 1990.

 

i want to go carb so i bought a edelbrock performer rpm with edelbrock 600cfm carb i believe its 1405

 

anyways so when it and did a trial fit it doesnt match. 3 out of 4 bolts would fit but the last bolt is off.

 

i assume that since i baught edelbrock parts that it would match i guess i was wrong.

 

do i need a spacer? how do i get it to work?

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Ok, I just realized you are talking about the carb bolting to the intake. At first I thought you meant you were trying to bolt it to the heads. Careful not to strip the threads on the manifold. Take some pictures and post so I can see exactly what you are talking about, but it sounds like you just recieved a defective part. Contact your part supplier and get another one. You shouldnt have to use any space, those parts are supposed to be made for eachother.

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Ok, I just realized you are talking about the carb bolting to the intake. At first I thought you meant you were trying to bolt it to the heads. Careful not to strip the threads on the manifold. Take some pictures and post so I can see exactly what you are talking about, but it sounds like you just recieved a defective part. Contact your part supplier and get another one. You shouldnt have to use any space, those parts are supposed to be made for eachother.

 

i will take a pic of it when i get home and try to post it.

 

the problem is that i baught it as a used product. so i wouldnt be able to claim it as defective since im not the original buyer.

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Oh, that kinda sucks. Hope you didnt pay too much, they are only like 400-500 for both new. You will probably need to drill out the hole in the one corner of the carb depending on what direction the threads are mis-aligned.

well i bought the carb for 80 shipped and the intake for 100 shipped since they were used and working condition i didn't think i would run into any problems.

 

if i drill out the corner would that mess it its design of flow?

 

maybe drill out little bit on each side?

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Are the bolts actually studs in the intake manifold? I was thinking Maybe it got dropped and bent one of the studs.

 

they are bolts. but even if i just align them they do not match. 1 hole is off by 2-3mm. i guess i will buy a spacer and see wich one is off.

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if i am reading the problem correctly i would say the best way would be to weld up the misaligned holes in the manifold and have them redrilled and tapped to suit the carby

alloy is pretty forgiving to work with

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I need to see a picture of the hole. I bet you can drill out the corner of the car to align it with the manifold. Where in Cali are you? Maybe I can swing by and give you a hand. Welding and retapping/drilling the manifold would not be worth the money, they are cheap to buy new. I have had this problem with a holley setup once before. My case wasnt quite as bad, and I was able to gently "force" my carb on.

 

It would be easy to mess up the carb or the manifold, so take your time and be gentle. Buying a spacer or adapter wont help you any, cause you are gonna have the same problem with the bolt spacing.

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I need to see a picture of the hole. I bet you can drill out the corner of the car to align it with the manifold. Where in Cali are you? Maybe I can swing by and give you a hand. Welding and retapping/drilling the manifold would not be worth the money, they are cheap to buy new. I have had this problem with a holley setup once before. My case wasnt quite as bad, and I was able to gently "force" my carb on.

 

It would be easy to mess up the carb or the manifold, so take your time and be gentle. Buying a spacer or adapter wont help you any, cause you are gonna have the same problem with the bolt spacing.

 

ya i though that too but i wanted to buy a spacer mainly to see which one has the flaw. if its the carb i would i would just drill the whole to fit. but if its the intake i would rather buy another intake. and a spacer would determine which is off.

 

so you know if the mesurement between bolt holes are all the same?

 

DSC02356.jpg

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They arent quite a square bolt pattern, but they should be symetrical. So measure the intake bolt spacing front to back on both sides and I bet you find the one side is a shorter length. Im willing to bet its the intake that is off, since they are cast then drilled and tapped. They sometimes dont get that last hole just right. Were it my stuff, I would drill out the hole on the carb and just use a fender washer. They dont have to be super tight anyway.

 

You could also use a jig saw and just cut out the portion of material in between the two holes.

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They arent quite a square bolt pattern, but they should be symetrical. So measure the intake bolt spacing front to back on both sides and I bet you find the one side is a shorter length. Im willing to bet its the intake that is off, since they are cast then drilled and tapped. They sometimes dont get that last hole just right. Were it my stuff, I would drill out the hole on the carb and just use a fender washer. They dont have to be super tight anyway.

 

You could also use a jig saw and just cut out the portion of material in between the two holes.

 

question is the bolt pattern on square bore carb different from spread bore carb?

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I thought you said the carb was a 1405? You should still be able to bolt it down to the manifold. Thats why there are 2 bolt patterns in the carb. I still say the problem is the manifold. But if the carb is a spreadbore, I would get a square bore for your car. You might want to Ebay both of those and get the correct new ones from Summit.

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Let's talk measurements instead of part numbers.

 

SQUARE BORE bolt pattern is 5 5/8 in. x 5 1/8 in.

 

SPREAD BORE bolt pattern is 5 5/8 in. x 4 1/4 in.

 

What is your carb bolt pattern?

 

What is your manifold bolt pattern? and...is it symmetrical?

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