Help build a 408 stock block 5.9!

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gregsdart

gregsdart

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I am helping a friend come up with a 408 stroker motor plan that will make over 500 hp, and if the desire strikes down the road, capable of handling some mild boost, say a max of seven psi or less. My personal thoughts are it would be a good idea ro go forged crank, H beam rods, forged pistons.
So far my friend has a good 5.9 magnum core that runs. Some consideration to budget would be great.
In our talks, a moderately high revving combo needing a 3500 plus stall converter would be fine. This will be a hot street build with a couple trips to the reack possible.
We are looking for suggestions for heads, cam, compression and ignition.
 
To set the stage for more power in years to come, i am thinking Molnar forged crank and H beam rods should stand up to more than the stock block can handle?
 
Food for thought. I built my 5.9 with stock crank, Wiseco forged 10.5:1 pistons and forged rods. EQ heads (no longer available) up top and a 7875 turbo that I’ve pushed to 12psi plenty of times without issue. 3500 stall also. This was really budget conscious.
 
subcom said:
Food for thought. I built my 5.9 with stock crank, Wiseco forged 10.5:1 pistons and forged rods. EQ heads (no longer available) up top and a 7875 turbo that I’ve pushed to 12psi plenty of times without issue. 3500 stall also. This was really budget conscious.
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I am sure it rocked, given that much boost and Heads. I built a 408 using EQ heads,pumpgas, made 518 tq and 504 hp. I thought i saw an add for EQ heads recently?
 
What fuel? The “boost later” plan kinda dictates a moderate compression ratio now and will keep the numbers down until that happens. If he’s ok with e85 once on boost, you can run the compression up high enough now that it’s not lazy NA, but careful piston selection is definitely a consideration to keep both (NA and boosted) combinations livable.
 
gregsdart said:
To set the stage for more power in years to come, i am thinking Molnar forged crank and H beam rods should stand up to more than the stock block can handle?
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This was the first thought in my head when I read the first post asking the question. Getting in touch Tom, our board member dealer of Molnar products can help with the compression ratio with the piston selection with the kit. Ultimately the C ratio should be under 9.0-1. Only because this provides a safe ratio to run NA and boost later with a reasonable cam size unde NA and boost later which is another salad bowl of worms to contend with. But the ratio isn’t so high to start with like you would do a NA build with new considerations to boost later.

I would think a cam in the 230@050 or so would not be to much for a 9-1 ratio and boost later to meet the goals.
MSD has a ignition set up capable of boost but I don’t know of anyone else off the top of my head that you may want to look into.
 
Talk to Doug’s son on Moparts who ran a turbo deal forever. Would answer all your questions
 
Icon Pistons IC982-030 Fits SB Chrysler Dish 34cc Bore 4.030

Icon Piston IC982 (specifically designed for boost) has a 34cc dish for use with a 360 running a 4” stroke.
This will net 8.8 to 1 CR with 65cc heads.
I believe this is the lowest CR possible with an off the shelf piston.

Definitely have the head and deck surfaces set for use with MLS Gaskets.
Run full groove main bearings for full time oiling to the rod bearings.
Run wide ring gaps as well.

X2 @PROSTOCKTOM is a Molnar vendor
 
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I will have to see what my friend choses to do. At this point, it will be 408 cubes, TF 190 heads, and if normally aspirated i believe 11/1 compression using a cam similar to what i used in my 504 hp 408 build, a Comp mutha thumpr 235/249/107. That motor tolerated 10,50 compression with EQ iron heads and liked 30 degrees total timing. One thing i did for that combo was a true 4000 stall 10 inch converter, and 20 degrees initial timing , 30 total, coming in slowly by about 3800. With a 3.55 rear and 2.76 low it was a beast in a 65 Dart.
I suspect when the owner looks at the compromise need for boost, the choice may be no boost/ high compression. In Minnesota BP sells 93 octane premium, which gives us a bit of an edge over some areas.
 
An 11-1 TF headed engine is IMO a very good start. I run a 360 @ that ratio and run a small hyd roller at 224@050 w/3.55’s on a 26 tire.

With 3.91’s and a properly stalling converter it’ll move out quite well.
My set up is pretty good with obviously the gear ratio holding it back for off the line performance. The plus is the car is very light for stock.
 
gregsdart said:
I will have to see what my friend choses to do. At this point, it will be 408 cubes, TF 190 heads, and if normally aspirated i believe 11/1 compression using a cam similar to what i used in my 504 hp 408 build, a Comp mutha thumpr 235/249/107. That motor tolerated 10,50 compression with EQ iron heads and liked 30 degrees total timing. One thing i did for that combo was a true 4000 stall 10 inch converter, and 20 degrees initial timing , 30 total, coming in slowly by about 3800. With a 3.55 rear and 2.76 low it was a beast in a 65 Dart.
I suspect when the owner looks at the compromise need for boost, the choice may be no boost/ high compression. In Minnesota BP sells 93 octane premium, which gives us a bit of an edge over some areas.
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My current combo : 410 c.i. 360 magnum block, 40 over, 4 inch stroker crank , Bullet 585/595 lift cam , W2 heads , 9.5 to 1 compression, Victor W2 intake , AED 750 hp, TTI headers , on pump gas: 545 hp. , 520 tq..... with a 904 , 4900 stall 8 inch converter , 4.30 gears has been 10.93 at 119

IMG_2398.jpeg
 
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