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Dual Plane Intake Question on Magnum 5.9

Tom Frost

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I know Air Gaps are considered a good intake for a carbed Magnum. My build is not super hipo...just a street cruiser with a slightly lopey cam...weekend cruiser. Are there any dual-plane options that work from idle to 4500 or so. I'll probably mostly be in the 3-4k range and don't need the high end power. Would a 4 bbl M1 work better for me? Don't want Chinese Crosswind if I can avoid it. Also wondering about tall manifolds/car/air cleaner height as I am putting it in my 73 Challenger with R/T hood.
Lastly, what engine mounts will I need (my old engine was a 318 LA) new is from a 1995 Ram 1500 5.9.

Thanks so much for any help. I am new to thye Mopar world.
 
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Chryco Psycho

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There are very limited choices for the Magnum carbed intakes , the bolt position / angle is different so it has to be specifically for the Magnum , no LA intakes will fit .
I know we used a dual plane on one build but I can't remember what it was . you will have to research magnum only intakes , I would look at Mancini racing , they often have a great selection .Roseville is the other great choice , both should be able to help with the left motor mount you will need & the better mounts such as Poly Lock or Mag mount .
 

moparleo

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Have you gone over to FABO yet ? Do a search on Magnum. Many have done the magnum swap and have lots of info. The M1 came on the factory 300 HP Crate engine from Mopar when they were first released many years ago. Only a few Magnum compatible intakes available. Edelbrock Air-Gap intake is the best but also the most expensive.
Crate motor specs were :
300 HP @ 4750, 375 lb. lbs. @ 4000, 9.5 : 1 CR. 1.925 intake, 1.625 exhaust, 1.6 : 1 rocker ratio. Cam 274/264 .385 intake. .409 exhaust hydraulic roller.
Basically the standard truck engine with a 650 cfm carb, M1 dual plane intake, stock electronic ignition , headers.
Buy this book.
NEW Mopar Crate Motor Installation Manual Book Sells for $30.00 Daimler Chrysler | eBay
 

Tom Frost

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Leo, thanks for the info. I will buy the book. Have been on FABO...lots of good info. Found a M1 for 300...and a new Eddy air gap for $250...buying it today. Thanks again. Any idea what left mr. Mt I use to put 95 360 where 73 318LA was?]
 

Chryco Psycho

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the 340 360 left engine mount we different from the 273 318 mount , so just a normal left 340/360 mount is needed
 

Chryco Psycho

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I have been building Mopars since 76 , I hope I learned something on the way !!
I am happy to help !
 

DrEamer

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Tom, have you had a chance to take the heads off the core engine yet? There is a chance that you might have what is called a transition block, which still has LA style oiling. If that is the case, you can use use standard LA head, ands a much greater choice of intakes too. Also, you can run a LA head on a Magnum block, you just need run the right parts to oil through the push rods.
 

Tom Frost

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Doc, haven't taken the heads off yet...but going to pressure wash it today and do so. Thanks for the info ...hope it isn't tho, as I bought a new Eddy air gap rpm for $250. Lol
I am thinking 750 Street Demon as they are good now being made by Holley instead of BG. Think 750 to much for a mild build? 625 is a bit small 670 probably just right. Cruiser...not hipo car.
 

Chryco Psycho

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Check Proform through Mancini probably cheaper than the Demon , if you stroke it it might be too small otherwise 750 is perfect on a 360
 

DrEamer

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Doc, haven't taken the heads off yet...but going to pressure wash it today and do so. Thanks for the info ...hope it isn't tho, as I bought a new Eddy air gap rpm for $250. Lol
I am thinking 750 Street Demon as they are good now being made by Holley instead of BG. Think 750 to much for a mild build? 625 is a bit small 670 probably just right. Cruiser...not hipo car.


Tom, there is no problem on the transition blocks and running Magnum heads, they just make using LA heads easier if you wanted them . The Magnum heads just end up blocking where the provision is in the block for the shaft mounted rockers is on LA heads. My block is a transition, and we ended up plugging the hole to mimic a regular Magnum block since I am using pushrod oiling. Nice score on the Air Gap by the way !!!
 

Tom Frost

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They look like they will, although I haven't test fit the engine in place as yet...using built 904 trans as I had it and didn't want to alter floor pan/hump for the 518. O'drive would be nice, but it will just be a weekend cruiser. Not going on the Power Tour. lol
 

Chryco Psycho

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I recall you said you were using the 904 , the clutch linkage could get in the way with the magnum exhaust manifolds but you should be fine with the 904
 

DrEamer

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I had it and didn't want to alter floor pan/hump for the 518. O'drive would be nice, but it will just be a weekend cruiser. Not going on the Power Tour. lol

Just for future reference, you do not have to alter the floor pan to put in a A518. That said, It does require some reworking, or buying a crossmember to get it to work along with some other basic mods.
 

Tom Frost

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Thanks. Your advice is very helpful...this forum is really great. So many helpful and knowledgeable people willing to help. I appreciate it alot.
 

Tom Frost

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Dr...that's good to know. I thought it would require altering the trans hump. I knew about the minor mods. Down the road I may go the OD route if I am driving it longer distances. Thanks again for the advice.
 
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