Carb’d 6.4 into a 70 Duster

[gumper]

Well my 410 seems to have snorted its last line of methanol (for anyone who has seen my “oil in water” saga). Going to rip it out, sell the good parts, and replace it with a 6.4.
My plan is a car 6.4, have the heads ported, a big nasty cam with MDS delete, 2” headers, MSD Hemi box and a 4500 intake with a big alcohol carb on it. That should get me to 600hp at the crank pretty easy, then funnel it through my 727. If I can find a lower mileage 6.4 I won’t bother swapping the pistons since I want to keep it capable of pump gas, and I won’t have a power adder.
Naturally I’ll have to get the proper swap mounts, flexplate, power steering delete, AC delete, and maybe other miscellaneous parts. Figure I can accomplish this under $15,000. After much consideration I don’t want to deal with EFI. Carbs are stupid simple, and they are predictable for bracket racing. Plus by the time I got all the EFI stuff it’d be at least an extra $5000.
Any flaws in my plan? Recommendations for cam makers?

 

[racerjoe]

Well my 410 seems to have snorted its last line of methanol (for anyone who has seen my “oil in water” saga). Going to rip it out, sell the good parts, and replace it with a 6.4.
My plan is a car 6.4, have the heads ported, a big nasty cam with MDS delete, 2” headers, MSD Hemi box and a 4500 intake with a big alcohol carb on it. That should get me to 600hp at the crank pretty easy, then funnel it through my 727. If I can find a lower mileage 6.4 I won’t bother swapping the pistons since I want to keep it capable of pump gas, and I won’t have a power adder.
Naturally I’ll have to get the proper swap mounts, flexplate, power steering delete, AC delete, and maybe other miscellaneous parts. Figure I can accomplish this under $15,000. After much consideration I don’t want to deal with EFI. Carbs are stupid simple, and they are predictable for bracket racing. Plus by the time I got all the EFI stuff it’d be at least an extra $5000.
Any flaws in my plan? Recommendations for cam makers?

It should be very easy to make 600HP with the 6.4. Keep in mine the stock pistons will limit your cam size.

 

[TT5.9mag]

From what I understand, it takes a significant amount of work (welding, grinding) on the gen3 single carb intakes to make them make power. I would start by contacting someone like Wilson manifolds for intake design/help.

 

[gumper]

From what I understand, it takes a significant amount of work (welding, grinding) on the gen3 single carb intakes to make them make power. I would start by contacting someone like Wilson manifolds for intake design/help.

I have a friend who’s just getting his porting business started so I figured I’d let him have his way with the heads and manifold.
Blackbird Performance builds ready to run 6.4s, and their 600hp version is mostly stock other than cam, ported heads and single plane manifold.

 

[TT5.9mag]

I have a friend who’s just getting his porting business started so I figured I’d let him have his way with the heads and manifold.
Blackbird Performance builds ready to run 6.4s, and their 600hp version is mostly stock other than cam, ported heads and single plane manifold.

Nice. I’m not sure what work was involved but I was talking to a guy at Irwindale (RIP) and his dart was running 5.80s with a carbed gen3. He said he had 100 hours in the intake alone. It was clear by looking at it, it had been welded, ground, and epoxied heavily.

 

[toolmanmike]

@Sublime one , What did you put in your car?

 

[toolmanmike]

Nice. I’m not sure what work was involved but I was talking to a guy at Irwindale (RIP) and his dart was running 5.80s with a carbed gen3. He said he had 100 hours in the intake alone. It was clear by looking at it, it had been welded, ground, and epoxied heavily.

9 teens would be a fun ride.

 

[gumper]

Nice. I’m not sure what work was involved but I was talking to a guy at Irwindale (RIP) and his dart was running 5.80s with a carbed gen3. He said he had 100 hours in the intake alone. It was clear by looking at it, it had been welded, ground, and epoxied heavily.

I don’t want to go near that fast. 6.4 in the 1/8 is as quick as I want. I raced an altered and a dragster for some years, and I don’t want to deal with chassis certs and the other slew of SFI safety crap you need to have fun.

 

[wish4hemi]

Mark Dudley Jr. runs low 6s in the eighth with his 700+ HP Blackbird Hemi just as a reference point. The 600+ HP Blackbird package plus a Prefix intake (or wait for the Blackbird intake to come out) might get you close your goal.

Dudley’s Blackbird Performance 6.4L-Swapped '74 Plymouth Duster Runs 6.0's - Mopar Connection Magazine | A comprehensive daily resource for Mopar enthusiast news, features and the latest Mopar tech

 

[gumper]

Mark Dudley Jr. runs low 6s in the eighth with his 700+ HP Blackbird Hemi just as a reference point. The 600+ HP Blackbird package plus a Prefix intake (or wait for the Blackbird intake to come out) might get you close your goal.

Dudley’s Blackbird Performance 6.4L-Swapped '74 Plymouth Duster Runs 6.0's - Mopar Connection Magazine | A comprehensive daily resource for Mopar enthusiast news, features and the latest Mopar tech

Should be no problem since I’d run it on methanol at the track. That’s good for 2-3 tenths over gas.

 

[Sublime one]

@Sublime one , What did you put in your car?

I am guessing you mean the Demon not the Cuda or Challenger? In the Demon I put a 6.1 Gen 3 basically stock for the most part with exception of some bolt on goodies. And the T-60 manual tranny. I love it!

 

[mopar65]

What about the Ritter single plane intake? Thats what I bought for my 6.1 stroked to a 420 gen3 hemi. I am going to put it in my 1970 duster. The 420 hemi has ran a 6.12 at 115 in the 1/8. The guy had it in a 3150 pound 78 Olds cutless. It's only 11.1 compression. To the op the only thing that sucks is TTI headers are on a 10 week wating period. At least thats what Mancini told me. I have everything to put the gen3 hemi in my duster, just wating on the headers

 

[dusterdoug]

Nice. I’m not sure what work was involved but I was talking to a guy at Irwindale (RIP) and his dart was running 5.80s with a carbed gen3. He said he had 100 hours in the intake alone. It was clear by looking at it, it had been welded, ground, and epoxied heavily.

‘63GT on here can attest to the efficiency of the Prefix single plane on my heap. After he slightly rubbed on my BGE heads to flow 360+ he flowed the Prefix intake: ZERO air loss. 600 Hp with a stock short block, a cam and a carb-ed intake is cake