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470 Stroker or 6.4L GenIII Hemi (Need Advice)

Started by dakota1, June 20, 2022, 01:10:25 PM

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dakota1

I purchased a 1970 Barracuda with a built 470 Stroker and A833 4 Speed (supposed to be around 620 hp and 600 tq).  The car was nicely restored Cuda tribute that was mainly setup as a race car able to run on the street.  The previous owner had a 470 Stroker B Block with Edelbrock Performer RPM Aluminum Heads, Ross Pistons, Harland Sharp Roller Rockers, Street Roller Cam that was said to be about
650 lift,  and a FAST EZ EFI (1st Generation FAST Carb Style EFI).  I was told the stroker kit parts were from 440 source, but I did not get any documentation on the parts that were used or any specs on any of the parts.  Supposedly the car and motor were restored or built about 10 years ago and had very few miles on it.

After only owning the car one season, the 470 Stroker is having serious problems as there is a bunch of bearing grease and shavings in the oil.  This is the 3rd oil change in less than 1000 miles performed by me (chasing down an oil leak) and the first time I noticed any problem.  The engine was still running (rough) and lost a little bit of oil pressure, so the engine has been pulled and it is at a local engine builder now to find what is going on.  We pulled one of the main caps and it is all copper colored, and the crank has some grooving.  The engine builder/machine shop said they may be able to cut the crank, and flush the motor and do a rebuild on the motor, but they won't know what I am looking at until they are able to disassemble and diagnose the motor.
 
This leaves me waiting to hear back from the machine shop but really considering the option of whether I should rebuild a 470 Stroker Motor or make the jump to a 6.4L GenIII Hemi?   Of course either option is probably going to be expensive and the machine shop diagnosis and estimate amount will factor into my decision heavily.  If I do rebuild the 470 I think I would like to move to Hydraulic Roller Cam and Hydraulic Lifters and Probably a Holley EFI System since the FAST system just never quite ran correctly.  I am a car guy, but I am not a mechanic by any means.  My guess is that if I tame down the 470 for a reliable street car, the power will be within about 50-75HP between these two motors and although the 392 will have a little less HP it will also be lighter weight.  To all the Motor Guys out there and the guys that have done Mopar Strokers or Mopar GenIII 6.4L Hemis, what are your thoughts? 

What would you do if the cost of rebuild gets up to 1/2 or 3/4 the price of a 6.4L Hemi??   

To the guys that have built these 470 or similar strokers, if you did it today, what would you recommend doing?

To the guys that have done 6.4L Hemi Swaps, if you did it today, what would you recommend doing? 


RUNCHARGER

The gen 3 hemi engines are ugly.
If you keep the B you won't have to swap in a new transmission, figure out a power steering pump, figure out mounts, buy a new exhaust system, reconfigure your cooling system etc.
Way cheaper and better looking to fix what you have.
You can use the money you save to buy a new style Challenger if you lilke, then you'll have one of each.
Sheldon

GoodysGotaCuda

Having swapped, I won't deal with another 70's engine. Ever.
1972 Barracuda - 5.7L Hemi/T56 Magnum
2020 RAM 1500 - 5.7L

My Wheel and Tire Specs


Chryco Psycho

Having built a lot of B & RB strokers they make a ton of reliable power , & as said above the car is already set up for it .
I am very picky about cam choice , if you go to a roller don't be afraid to rev it , the rollers have no oiling & will starve if idled & lugged a lot , I generally use flat tappet solids as my preference but you need special oil or that will not live either , EDM lifters can help in both cases as some oil is fed from the bottom of the lifter . The cam in there may be the best choice over spending a lot again for less .
I am not a fan of the needle brg rockers for street use or alum rockers & prefer bushed stainless rockers as you have a lot more contact area .
Yu already have the Eddy heads ,  IMO there are cheaper heads offering the same performance & there are far better heads in the same price range as Eddy

1973Cuda

I replaced my 383 EFI/MSD engine, aluminum intake and mild cam with a crate 6.4 and couldn't be happier ('71 RT). Definitely took a hit in the wallet!

dakota1

Quote from: 1973Cuda on June 21, 2022, 05:27:38 AM
I replaced my 383 EFI/MSD engine, aluminum intake and mild cam with a crate 6.4 and couldn't be happier ('71 RT). Definitely took a hit in the wallet!
If possible, would you PM me with a guesstimate of how bad of wallet hit you took?  I understand if you don't want to share public, but if you PM me more specifics, I would greatly appreciate it.  Also what Transmission did you end up using? 
Thanks for the reply and input!
dakota1

anlauto

Quote from: 1973Cuda on June 21, 2022, 05:27:38 AM
I replaced my 383 EFI/MSD engine, aluminum intake and mild cam with a crate 6.4 and couldn't be happier ('71 RT). Definitely took a hit in the wallet!

I really like how you painted the coil pack covers  :drooling: :thinking:
I've taught you everything you know....but I haven't taught you everything I know....
Check out my web site ....  Alan Gallant Automotive Restoration


dakota1

Quote from: Chryco Psycho on June 20, 2022, 07:50:36 PM
Having built a lot of B & RB strokers they make a ton of reliable power , & as said above the car is already set up for it .
I am very picky about cam choice , if you go to a roller don't be afraid to rev it , the rollers have no oiling & will starve if idled & lugged a lot , I generally use flat tappet solids as my preference but you need special oil or that will not live either , EDM lifters can help in both cases as some oil is fed from the bottom of the lifter . The cam in there may be the best choice over spending a lot again for less .
I am not a fan of the needle brg rockers for street use or alum rockers & prefer bushed stainless rockers as you have a lot more contact area .
Yu already have the Eddy heads ,  IMO there are cheaper heads offering the same performance & there are far better heads in the same price range as Eddy

Chryco Psycho - Thank you for your detailed response and your knowledge on the subject.  I know you have always offered up a ton of great information to people and I have read posts where you have been involved in both stroker builds and 6.4L swaps!  Maybe once the machine shop has the motor torn down I can message you with some more specifics and if I decide to have the 470 rebuilt, then I can get your opinion on some of the parts choices.  The shop I am using has a very good reputation for with circle track and drag race crowd, but like most shops they know chevy 100x better than they know mopar.  At this point, the rockers are Harland Sharpe Roller Rockers 1.5 I believe, but I don't have any actual CAM specs other than being told that it was a street roller with about 650 lift. 
Thank you again for your time and input, it is always appreciated!
dakota1

dakota1

Quote from: GoodysGotaCuda on June 20, 2022, 07:47:58 PM
Having swapped, I won't deal with another 70's engine. Ever.
Goody  -  Can you go into more detail or give me more specifics as to why you feel that way.  What are some of the biggest differences or improvements that make you feel like you would never want a 70s motor again.  I appreciate your input and opinion and this is the sort of opinions that I was hoping I could get from this post. 
Thanks,
dakota1

rebelyell

I'm deep into collecting parts for a 6.1 swap.

Prepare to open your wallet. You can make the a833 work with the new motor. Minor adjustments required.

At minimum you'll need the fuel supply worked on. new motor needs around 8-10x the current psi.
motor mounts ($200)
headers ($1000)
radiator (whatever you want to spend)
harness ($1800, plug and play from hotwire comes with pcm)
Holley or Milodon oil pan plus main bolts ($500)

These are just some of the main components. And also assuming you find a motor that doesn't need the front cover changed or worked on.

I'll probably be $20k into it when it's all said and done. You could spend half that and drop a new motor in that will probably do everything you want. And you're going to need slightly more than basic grease monkey "I swap parts" skills. This is going to test every skill I've ever thought about having. I wanted the extra fuel economy (I did not swap this for that reason), reliability, and cool factor. I want this car to be a mix of new and old. Having had a new challenger and driven this one for a while I knew that's what I wanted.

Chryco Psycho

Plus & minus with a modern Hemi , better sealing , no leaks , Efi & tuning is far better but you can do Multiport EFI on a big block also , I have done it & the results are amazing but it was close to $5k to complete the EFI unlike the throttle body efi most are selling now .
EFI is so much better , carbs are basically a controlled fuel leak by comparison , the block will last forever as you do not get the excessive fuel wash & wear , cold starts & drivability as well as increased fuel economy etc .
The downside is the modern Hemis do have lifter issues & need to be revved often to keep the roller lifters oiled enough .


Chryco Psycho

People probably wonder why I hate Eddy RPM heads
About 18 years ago when they first came out my friend had to have a set for his bracket race car , we dynoed his engine with my ported 452 heads on then did the swap & $3500 later returned to the same dyno , the 452 heads made 308 RWHP , the Eddy head made 311 RWHP so $1000 / hp gained , I can find HP for a lot cheaper than $1000 / hp !
The other story involves the small block heads & A friend that worked at the speed shop checked through an order of 10 sets & hose the best 2 , he showed me how poorly they were cast with massive core shift .
If you want similar performance the 440 Source heads are 1/2 the price , if you want better performance Trick Flow has far better heads for the $ spent ...

dakota1

Quote from: Chryco Psycho on June 20, 2022, 07:50:36 PM
Having built a lot of B & RB strokers they make a ton of reliable power , & as said above the car is already set up for it .
I am very picky about cam choice , if you go to a roller don't be afraid to rev it , the rollers have no oiling & will starve if idled & lugged a lot , I generally use flat tappet solids as my preference but you need special oil or that will not live either , EDM lifters can help in both cases as some oil is fed from the bottom of the lifter . The cam in there may be the best choice over spending a lot again for less .
I am not a fan of the needle brg rockers for street use or alum rockers & prefer bushed stainless rockers as you have a lot more contact area .
Yu already have the Eddy heads ,  IMO there are cheaper heads offering the same performance & there are far better heads in the same price range as Eddy

Chryco Psycho  -  It sounds like one of the roller lifters went bad and has destroyed the current cam.  It does sound like I will probably be rebuilding the 470 since I caught this early and there wasn't a ton of damage other than cam and lifter.  If I replace the cam, I think I would like to move to Hydraulic Roller Cam and Hydraulic Lifters.  I am considering the Comp Cams XR292 Here is the sales info on that cam.  Please let me know what you think regarding how this would work in this 470 Stroker with 4 Speed and 3.54 Dana Rear End.  It has Edelbrock 75cc Performer RPM Heads that have been ported and now are 83cc and it has Harland Sharpe 1.5 Rockers.  Sales rep at 440 source recommended this cam for my scenario... but I would like to get additional opinions....  I would like this to create a fun, strong, street car that creates between 575 - 625 HP and TQ.  Also plan Holley Sniper EFI.

cam: 
Comp Cams Hydraulic Roller Retrofit Cam - 242/248 - 549/.544
This is our mid sized choice from Comp Cams, which works great for most street/strip stroker motor applications. In a 500/512" stroker, this cam will make power from about 2500-6500. The .549/.544 " lift and 242 intake and 248 exhaust duration at .050" allows for nice low end power without giving up strong pulling up top. These are ground on a 110 degree lobe separation angle. We'd use about a 2500 stall, and some decent rear end gears (3.55-4.10 for the street.)

lifters:
Howards Cams 100% USA Made retrofit hydraulic roller lifters are true high performance street lifters designed primarily for ease of maintenance and reliability. They "drop into" a stock block with no machine work or oil system mods required, and work with all the steel billet hydraulic roller cams we sell, regardless of brand. The lifters are CNC-machined and then fitted with precision check ball internal valving to prevent lifter "pump up." These features combine to provide a broader power band and increased rpm potential, while still offering the low maintenance of a hydraulic cam. These are designed for street performance enthusiasts who want to upgrade to a hydraulic roller camshaft. They are manufactured to fit early or late model blocks, including blocks with tall lifter bosses. Howards Cams uses cold form technology to shape their bodies for durability. The lifters are then carbonitrided and tempered for hardness. They also feature hardened and tempered steel alloy roller wheels, heat-treated stainless steel cross bars, and high-alloy steel tie bar buttons. Howards Cams Street series retrofit hydraulic roller lifters are specifically designed for street applications up to 6,500 rpm.

Thanks
dakota

Brads70

I have a lunati hyd roller in my 451 . Its been 10 years now with no issues.

dakota1

Quote from: Brads70 on July 09, 2022, 06:15:32 PM
I have a lunati hyd roller in my 451 . Its been 10 years now with no issues.

That's great to hear.  Do you have any specs on your motor build and cam, just to see how it compares to what I am putting together?  Thanks again for your reply and info...
dakota