Fellow Moparts Brothers- Please help me decide:

The next project I have coming up will be a 70 Bee.

The car will be a street/ strip deal and will have a 727 with a Dana 60

The car will be a normal weight for a B body of that year, with a roll bar added.

I have no current E.T. Goals, just want to build a fun car.


I have 3 choices for engines in the shed, please complete the poll and maybe a brief explanation of why I should build one over the other. Thanks! HH

Street strip car, 6.4 hemi.

Reason power vs drivability will be better.

Whichever makes the most torque, not knowing if a turbo's in the Gen3 plan, or the gear/tire in a heavy street car. Low-decks are easier to service than RBs, as well as their other advantages.

The car I've been building in my head for some time would look like a stock 383 '68 Road Runner, but would be as light as possible with a 500"+ low deck.

The gen III would be naturally aspirated. Looking for big torque. AndyF's builds also have me wanting something like a 505.

I am afraid the gen III will seem so soft down low compared to a stroker.

I've made more HP and torque on all of my pump gas low deck 400 block stroker motors that I did with similar C.I. gen two 426 street hemiroid motors with similar carbs
I had to learned to trust the results(track and engine dyno tests) of these build and I now concentrate on getting the best heads I can get to start with and go from there
BTW, I like and use 4.250 and 4.300 stroke cranks with 2.200 rod journals on these builds with the longest BB Chevy type rods I can get away with, 6.700 or 6.800 with .990 pins and a custom piston order for that specific build
My first 511 C.I. 400 block stroker made 612 HP at 5500 RPM and 644 Ft lbs at 4500 RPM with a mild set of 906 heads with big valves(2.14 and 1.81 ex.) and a low deck sixpak setup
That same motor with a .050 longer stroke crank, went from 4.25 to 4.300 to increase the comp. ratio from 9.25 to 1 to 10.3 to 1, ended making 775 HP at 7500 RPM with a ported set of 440-1 with 2.250 intakes on Oregon pump swill at 4300 ft elevation on a calibrated DTS engine dyno with a stock 400-3 intake and 1050 Holley Dominator carb

I voted 6.4 but it was tough. Would you be stroking the 6.4 or just run it as a takeout? Keeping VVT? 6.4 is a great engine, awesome flowing heads and a stout block, BUT, a 400 stroker (4.25" arm) would be a very nice street package. Sure, the Apaches flow 330-340 ish stock, but you have to twist 392" pretty hard to take full advantage of it. A 500" BB with some street type heads (trickflows, edelbrocks, etc) would make a mountain of torque which is nice for a street car.

I voted 6.4 mainly for great drivability with the right o.d. trans and the right rear gear.If you want killer instant insane low speed torque , top that 6.4 with a twin screw blower and hang on. It will need forged pistons and good rods.

Hemi.....You either have one or you want one.

I chose the Gen III but with a couple of conditions.

Keep the EFI and at a minimum run a 46RH trans if you don't/can't keep all the boxes it takes to run the engine and a NAG1.

A 70 Bee should scale out at least few hundred pounds lighter than an LX so it should be sporty to drive plus economical.

This choice ignores the challenges of swapping in an engine that doesn't belong ie mounts, accessories, headers etc.

My second choice would be a 4.25" stroke 400 with CNC Stealths or less stealthy Trickflows dressed up as a 383 stock valve covers and all. Hydraulic flat tappet and use the money saved from the roller towards a FiTech or similar EFI. 727 with 3.23 gears max or whatever OD option that suits you that will give you 3.91/4.10 type launch and 3.00ish cruise.

No way the 400 stroker will be as fuel efficient as a Gen3 but it won't be boring. It will also bolt in with little to no grief depending on your trans choice.

Kevin

Thank you all for the replies. If I do go with the 6.4, I would be putting in forged rods and pistons. A good note to remember is that a B body will be lighter than an LX. Funny to think that a B body will be the lighter weight car. LOL.

I have never experienced a big block stroker, but I can imagine that it is exhilarating. For those with experience, will I be satisfied with a 6.4 compared to a stroker? I know the rear gears and setup will be quite different from each other.

The 6.4 has more potential apples to apples period. Plus they are very easy to crack 600hp on pump puke. The difference is they also do it with STOCK valvetrain and juice lifters 0 maintenance. No $1000 lifters, $1000 rockers or $2-3K to get GOOD heads needed. THAT is why I made the change.

Prefer the K.I.S.S. principle myself. Low deck stroker, plenty of options for parts.

Guys I really appreciate the information here. You all have built way more than I ever will and hearing about some of your combinations is cool. I am still undecided, but all the info is helping.

72 Swinger, If I remember you had a big block before you did the gen III. Does the new hemi pull as hard?

That would be 2nd gen!

And one more thing,,,,,BOOST is a wonderfull thing!!!!!

2nd gen would be cool, but I don't have a block. Anyone have a good one for sale lol!

I said GIII because the B/RB strokers have been done to death.

Torque-shy engines need gears. For that, the 727 is not a good choice.

If you are dead set on a 727 I switch my vote to 4.25 stroke 400 block with the Trickflow heads.

R.

Either the 400 or 440 with a 4.25 crank.
I'd probably do the 440 myself...... The header choice situation is slightly better along with main bearing choices.

When I built my Duster I literally lost sleep over this very subject, which engine combination to go with.
I planned on a Gen3 Hemi but all the prices were adding up too fast, then I decided on a stroked small block but I ran across a super stock drag racer selling a brand new 500" low deck(400)stroker kit and I am glad I went that route since I wanted to run a 727, 3.23 gears, and a fairly tight converter along 10.5 to 1 pump gas compression and a mild solid cam.

Header fitment is a big issue with the big block A-bodies and working on the engine and trans and starter can be frustrating but other than that it is such an awesome combo for the street. I cruise my Duster every sunny day, never runs hot even on a 95 degree day, gets decent gas mileage and it will literally do a smokey burnout at 50 mph! Very fun combo.

Prosport: beautiful car. Thanks for the insight!

It does everything better, with 1/3 less fuel. The torque isnt as broad, but good gawd. Keep in mind I have a 420" Gen III though. Ray Meyers is a great example of a comparison, he had a way more stout BB than I did.

Thanks, I wonder how a blown 392 gen III would compare to a big block?

There would be no comparison, a Whipple at 10lbs is usually a 700RWHP combo. Pump gas mind you. I was going to build a 400/499 deal and after I did all the math, for the same money I gained EFI in the process. And no valve adjustments, phantom oil leaks or questionable block strength. Like I said earlier, to have the same power AND reliability, you need a solid roller in a BB. Once that bridge is crossed, things start adding up to get daily driver reliability.

Bigblock stroker is what I would do and did do on my 63 but its not real big. The 400 is the best to use if you are ok with the intake selection on the lowblock. I went with the 440 because I may go to a crossram one day and I knew I only planned to make around 600 flywheel hp. If I wanted to make closer to 700 hp I would either go with the 400 block or a aftermarket 440 block. The new Hemi's will make great power but I just like seeing an eng that looks kinda like what came in the car.

And Prosport that eng looks awesome. Bottom line is you only have to please yourself. Also have you done a price comparison of the new Gen III Hemi vs the 400 or 440 setup ? Ron