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Discussion Starter · #1 ·
Ive built a 1969 340 full roller motor and put all the modern EFI and magnum heads on it in a 1996 Dakota. just throwing it up here to see if anyone is interested in seeing more of it.

it makes an estimated 400-425 hp.
 

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Discussion Starter · #5 · (Edited)
I will give that a shot.

Ive got a 1996 Dakota Sport, regular cab 5 speed

So for this motor. Here are the specs:

1969 340 block (used Schumacher motor mount kit)
Bored 4.080
Factory Forged 340 crank
Eagle Forged H beam rods
Speed Pro forged .040" pistons
Comp cams HR custom grind .556"/.544" thumpr cam
Retrofit Roller Lifters
EQ Magnum 2.02" Heads
Hughes 1110 Valve Springs
Comp Cams Ultra Gold 1.65:1 Full Roller Rocker arms
Mopar M1 Singe Plane Manifold
24 lb injectors
2x58mm Big Bore throttle body
March Performance Underdrive Kit
MSD Coil
MSD wires
Accel Spark plugs
Polished Shorty Headers

Truck RIPS! I estimate that it makes around 400-415 HP
 

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How did you modify the block to support Oiling threw the push rods (which is a better design for rocker longevity)? I assume you blocked off the oil passageways with some sort of plug. I'm just curious, because I'd love to build a 416 stroker, based off the 340 platform, and use all of my magnum topend stuff on my 390 stroker currently. That would be a rather fun setup. That or get further into the modern hemi stuff.
 

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Discussion Starter · #10 ·
The block already has oiling provisions for the lifters. so I just used retrofit hydraulic roller lifters, and oil through pushrods. I had the machine shop clock the cam bearings to block off the oil passage to the heads. you have to make sure you still have a hole lined up for oil to the bottom end on your cam bearings, if the bottom hole doesn't line up, like mine didn't, then you have to drill a hole in the bearing.

I also recommend drilling, tapping, and plugging the oil hole on the firing deck to the heads. I didn't do it but I will in the future for extra security.

As for rocker longevity, I am running Comp Gold full rollers. they have an oil hole on the back and the oil comes right up through the push rod. I tested my oiling by spinning the motor over with the valve covers off until I built oil pressure and could see that my oiling system was working fine.

As for the bottom end, I am currently running a 318 magnum crank for the time being. but I have a steel 340 crank that I will probably use. if you get a 340 with caps, the rear cap wont work for a magnum oil pan. I had to use the magnum rear main cap in order to use the magnum oil pan gasket. they mic out the same ID, but the 340 rear cap is bigger on the outside because of the different oil pans. Also, using the magnum rear cap allows the use of a magnum rear main seal.

the magnum heads went right on. im using stock length hardened pushrods from edelbrock. I think its part number EDL-9644 from summit. I THINK. I know that they 5/16, are 9.638 long and .080 wall hardened push rods. I bought some rocker studs from Hughes for the heads, and then went with stud mounted rockers. adjusted everything out and it runs great.

if you have anymore questions let me know. i'll post pictures and info about the whole build up
 

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I'm running the EFI on a '73 block with Mag heads. I'm running an LA front on it, including the RV2 compressor so it's not nearly as clean... It's been flat tappet but I think that's gonna change- if I get over the sticker shock. I've got a pretty solid '73 340 block that was blown up in the '80s. Lots of machine work needed, but for the pricetag I got it for as a core long block- cannot complain. I think it's an excellent start to a solid 420" stroker or something along those lines...

Which lifters did you go with- Comps? Can't believe how expensive they all are...

That's a fascinating solution to the problem you came up with on the rear main- the 318s got different caps '92-on so they would use the same pan as the 360 which has a different rear seal surface. Typically the 318 pans flood around and are worth very little while 360 pans on the older stuff are less common, so most wouldn't have thought of that. Interesting on the cam bearing too.
 
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