Please let me know what you think about this 455 build

Thank you everyone, you have a wealth of information and are willing to share it. As some of you have reccomend I will get the molnar rods. More than one of you has suggested a custom cam from Scott Brown or Bullet cams, when it is cam time I will go this route. I also plan on emailing Mike at TA to see what he thinks as suggested. I am also considering going to Jim Weise at Trishield performance for the machine work as he is only a couple hours from me. As this is part of the planning stages this engine realistically will not see the light of day until next summer. In that time it seems I need to address the transmission/rear gear situation to optimize the capabilities of the engine as a street machine.

 

And Holley techs will swear to the moon and back that we only need 725cfm to feed our 464's because they only turn 5500 or 6k rpm but yet we all know that 850+ cfm works better so what is "correct " on paper often doesn't equate to what really works best

 

if this build had 3.73 gear I would say it would love 900+ cfm. but with those gears the rate of engine rpm increase might make a carb that big troublesome.

 

Just curious,...So if us guys that have owned multiple BBB's in multiple different chassis and combos, are so in the dark,...what should he build? lay us our your build parameters,...and if it includes stock heads with big valves and a fisher price my first camshaft ,...I along with alot of other guys will jerk his front bumper off from a dig or a roll,...I mean in my mind a mid 11 full weight street car is about the limit b4 things get too rowdy to really enjoy on long cruises etc, but a mid 11 sec full weight car with iron heads that will happily sip 93 octane and run power brakes is all but a pipe dream 90% of the time

With a 500in twin turbo car, I would imagine you have experience with power management,...why the hell would one loose sleep over 15,20 30 or even 50ftlbs when there is already an abundance below 3500 to knock the hides off,. When you could gain 50to75 hp through the entire range? Where is the downside or risk??

 

The acronym for that true statement is: B.U.I.C.K!

 

I believe TA heads are great! they do work ! they flow fantastic,
on a race car, or hi horse power street car,
but on a mild street car, I see no reason to spend the $$$.
if you are looking for UNDER 500-550 hp, iron heads are fine
ported iron heads work very well, on mild street car.
the issue I have with big port, hi flowing heads, ON A STREET CAR, with mufflers, etc.
they would never , or seldom ever be used fully,
OP stated 5500 rpm, and 2.91 gears, so mild cam and iron heads would achieve that
AND be fun to drive,
I've seen way to many people with big heads, big cam, big headers, and its a DOG
ON THE STREET!
not going to get into the carb size battle,
but dyno results , show to big of a carb affects drive ability , and
poor fuel atomizing . resulting in poor VE,
race car, sure go big,
street car... use what drives best,

 

the problem I see with the iron head route, most shops now stays are getting 700 plus to just redo iron heads.....no porting.....so why 1500-1700 into iron head were jus a few bucks more you will already have better flowing head out of the box than "most" places into country could ever get out of iron head. the op says street......what happens if in a few years he wants more then he has very little room to grow.

I agree iron heads make good power, I ran a set for 20+ years and touched the 10s with them. but from a scratch build and bang for buck I have s hard time getting there the value. now if you find a fully ported set for a steal, might change things.

but as another member stated the benefit of ease of header install sounds drastically better on his car with the stage 2. and that counts for something too, making it as serviceable and easy to work on too.

 

The Stage-2 SE heads are excellent for the street, part throttle response is phenomenal and street tires are useless at full throttle.

Bob H.

 

I personally will never build another set of iron heads again, unless as others mentioned you get a killer deal on a set already done, or you've got some racing class restrictions that require iron heads. By the time you add in valves, springs, keepers, guides, machine work, porting, yadayada, you could've had a set of aluminum heads that'll run circles around them for the same money. I've done it both ways, and it just doesn't make sense anymore, especially with the ability of the aluminum heads to take more compression or timing on pump gas vs an apples/apples iron head. Plus, you might as well "build for the future" as very rarely is a guy ever really satisfied 100% with what he builds the first time around. You've got enough cubes that if you're missing a little bottom torque, you're never going to notice.....If you keep your 2.91 rear gears or add an overdrive, your engine will be lugging quite a bit under light throttle rolling down the highway. You want as much pre-ignition prevention as you can get, and aluminum will help with that.

EDIT: And I can't remember who mentioned a 5.0 Mustang, but they are correct. A 5 speed car would've come with 2.73s. They would actually go faster on the top end with 3.55s because you could use 5th gear instead of 4th, and they'd get better fuel mileage with the lower gears (numerically higher), all the while being much quicker and fun to drive.

 

After reading this thread over again and doing some research it seems like I definitely need deeper gears, like 3.73 and most likely overdrive. I have put different gear ratios into calculators and find that 3.73s and 3 speed gets me 3100 rpm and with od .7 2200 rpm at 65. 3100 seems loud and high for a couple or more hours on the road going places. Sounds like 2200 maybe too low from some of your comments. I usually drive the highway at 75 so 3600 vs 2500. I also do not need to have a top speed of 150+. Are 3.73s with od the right path or am I creating the same (too low rpm) or another problem?

 

3.73s and OD is just about perfect for a good do everything set-up, in my humble opinion.

 

You’re on the way to creating a strong recipe for an both an exciting street and strip vehicle. The 700R4 has a 3.06 first gear, as well as overdrive, so you have a lot of potential to keep rpms up and the engine not bogging at cruising in town speeds as well as overdrive with 3.73s to fly along the highway at a reasonable 70-75 around 2,500 rpm. Have a look at how hard your car will accelerate with a 3.06 first gear.

700R4 with 3.73 first gear acceleration.

3.06 x 3.73= 11.41

TH400 with 2.91 first gear acceleration.

2.48 x 2.91= 7.22

Run these gearings through your calculator, with your included tire size, and begin to imagine how even your stock engine will perform with the gearing that it should have come with from the factory.

 

I personally dont like 700r4 behind a big block. tbe 3.06 1st ratio tends to be too steep and 1 you roll the tires very easy, 2 it flys by very fast, 3 the gear spread is very far between 1 and 2, and lastly the take alot of hard parts to live.

a basic rebuilt on a 400 with shift kit and hd sprag will live behind that motor all day and will be under 1500 with trans and custom converter. by the time you do a gear vendors od you will have a touch more in it, but it will hold tons more power than a 700r4, you cable to mess with or adjust, fits where it should. and you can actually use of in every gear......so if you wanted to **** it back and forth you could have a 6 speed. there is situation where 2od is use full........hills in particular where 3 is not enough but 2 is too much

the 400 with 3.73 or even 3.64 gives you a close to 9:1 effective 2st gear ratio. with a street big block that's perfect

 

And this is the nature of opinions and ideas, but I certainly like your idea and reasoning too.

 

That depends on which O/D transmission you choose?

With the 2.91 rear gears you have and the right cam with the power range from just off of idle to 5,000 RPM, the 700R4 would work well. Granted the 700R4 likes at least a 3.08 rear gear to be happy @ 45 mph in O/D but with a cam that brings the power curve in just off of idle with a BBB 455 torque, the engine "lugging" shouldn't be a problem.

The 200R4 wants a minimum of a 3.42:1 rear gear to be able to shift into O/D @ 45 without lugging the engine down. Even with an off idle power curve the mighty BBB 455 will have a problem @ 45 mph with a 2.91:1 rear gear.

With a TH400 you can use the 2.91:1 rear gear but you won't have the added gearing in 1st gear the O/D transmissions will give you so even going this route you would more than likely want to change the rear gear.

A 9.5:1 1st gear multiplication ratio for a street car is about optimal unless you want a tire burner that would be WAY to easy to spin the tires!(spinning the tires every time you press the gas peddle more than 1/4 gets old REAL FAST!)

So with a th400 you would want the 3.73:1, with the 700R4 a 3.07 and the 200R4 a 3.42:1 to be the closest to the 9.5:1 1st gear multiplication ratio.

 

I like gear spread in the 2004r better. the 200 comes in a universal belhousing so it fits directly.

but it does take alot of upgrades to live behind big tongue. but his is the trans that most are using behind turbo v6 motors in the GN.

it also has a TV cable to adjust to get to work correctly. but the 2004r will allow shift into od at wot if your going that fast ever.

as with any build figure out total cost, where you can save and where you want to spend

 

You may have hood clearance issues with a single plane intake on a 67.

I'm running a 3.08 gear with a th350 trans behind my 455 and the rpms are not too high on the highway. Your 2.91s will be fine with a th400.

My 66 ran a traction limited 13.5 @ 103 at BG last year with stock heads and a TA 288-94 cam and is pretty responsive on the street. You just need to match your cam to your compression ratio, recurve your distributor and get your carb dialed in and you should be fine. Plan your build, but don't overthink it.

 

I removed Tomlinson-ported 67 big port heads and installed TA stage 2 mild ported heads.
Tremendous difference! No downsides to city crusing either, with a mild cam.
Expect about 40 or more hp and 60 lbs less weight. Better valve seats too. Go with stage 2 heads to give more header clearance. Get jet hot coating inside and out to dramatically cool everything under the hood.
Make sure the dipstick will snug in completely before, during and after installation, unless you dont think you'll need one.
A MILD CAM can run smooth and not suck your tank dry. But can really tickle your tummy and give you a dopamine rush. A 288-94 cam would be worth considering.

 

I have a 200R4 with a lockup on a switch with 3:73 gears. Stage 2 heads. The car runs fine on pump gas and in lockup turns 2200 at around 70ish" My speedo doesn't work". This is a perfect combination for me because I will drive in 30 miles one way for dinner.

 

Forgot to mention that TA doesn't have any heads right now and doesn't know when they will be getting any.