Some of you guys may remember me posting this combo back some time ago, but I wanted to throw this out on the table for critique once more since I have changed by mind on a few components and just in case someone may be thinking Street Mountain Motor madness like myself!

My whole concept here is to simply have a low RPM, big inch, pure street motor (well, maybe 2 or 3 visits to the strip per year) and have very good streetability/reliability. I think the following combo is close to my objective, but please let me know what you'all think and what you would modify or change.....

1967SS Chevelle
510 BBC
454 (bored .060) - "0" Decked
4.375" Forged Stroker Crank (internal balance)
6.385" Rods
SRP Forged Flat Top pistons
LUN 288/296 Hyd Cam 231/239, .550/.575, 110 LSA
GM 063 Closed Iron Ovals (light port work)
2.06/1.72 Stock Valves (performance valve job)
Edelbrock Dual Plane Intake
Edelbrock 850 CFM Qjet
HEI Distributor
Hedman Headers 1 3/4" long tubes
Max. RPM under 6000

TH400 (Rebuilt w/shift kit)
B&M 2400 Converter
3.31 12-bolt Posi

Final CR - 10.1
DCR - 7.9

I realize that due to the trememdous torque, the stock suspension will need upgrading. This will not be a race car by any means, just a big bruiser roaming the streets! :D

Thanks for any help. Charles

I like it as a street cruiser for sure. I wouldn't plan on taking the BM to the strip too many times though with the big motor. I suggest a Transmission Specialties XHD 10" Low stall. about $450 and can take a beating as I know personally.

No need to do anything to the suspension though, No aftermarket suspension will help with street tires and the torque you will have. urethane bushings and box the lower arms with a $30 boxing kit. Also add the upper-to-lower rear control arm triangulation braces (this is a must to help eliminate cracking the rear upper cross member).

The B&M should hold up on the street, I ran a 11" B&M holeshot for 4 yrs in my car and 2 yrs full time racing,not a 510 but a pretty healthy 461 :D held up to many low 12 high 11 passes. I like the SSM liftbars for all around traction help, I ran a best of 12.69 on street tires with a 1.86 60ft time.

Originally posted by Rapid Robert:
The B&M should hold up on the streetI agree Bob. I ran a BM 2400 for 3 years into the 12.60's myself. I was thinking the heavier duty converter would be a decent upgrade with the Bigger Inches. I had a converter go bad on me and it ruined my crankshaft.

But yes, for street use the 2400 will be OK.

Would the Stock TH400 w/shift kit be adequate under "normal" use?

About the only other concern I would have is the large 4.375" crank clearancing issue that someone voiced a while back. I don't think that there was a clear concensus about it dropping right into the 454 block versus having to remove much material to make room for the longer throw of the crank. As I understand it, a 4.25" crank should be a cinch, but, the 4.375" would probably present a problem.
Maybe this particular crank/block combination is one that hasn't been tried very much? :confused:

Charles

I dont think the clearancing will be all that bad, the three 454 blocks I've installed 4.250 stroke cranks in hardly needed any grinding at all. The .125 longer stroke would only pass about .065 closer to the block. But, I have not personally fit a 4.375, yet.

I think you would be cutting yourself way short with those tiny ports/valves on a 510 cube motor. I would at least go with 2.19 intakes,1.88 exhausts. JMO
Steve

Looks like you have the making for a real nice street motor. graemlins/thumbsup.gif

If it were me, I might make a few small changes if you are going for the most streetable power without giving up any reliability.

First I would having the heads done with either 2.19" or 2.25" intake valve along with 1.88" exhausts with a good port (bowl) work.

Next I would think about a solid flat tappet cam with similar specs to the Lunati you have picked now. Something like mid-to-high 230's on the intake and maybe mid 240's exhaust with a 108-110 LSA. Solid lifter cams are no problem and require very little maintnenance. (once a year for the lash).

Last on the intake you stated an Edelbrock dual plane. Just make sure its the Performer RPM and in your case it needs to be the spreadbore design. This manifold is a lot nicer than the standard Performer.

Just food for thought. smile.gif

Took my holeshot to 9.32

And raced it for 4 years. went 10.70 without nos, Changed to an A1 custom 10" and went 9,96 instead. and 8,88 with spray. ;)

Kill som torque. Get an single plane, larger cam.

Its an pain driving with that much tq. Spinning tires all the time. Transmission rebuilds once a year etc.

Kill some torque :confused:

Isnt that the reason we want big motors :confused:

thats what it takes to get these 2 ton automobiles down the track graemlins/thumbsup.gif

Sounds like a fun combo to me.
I wouldn't change a thing..maybe keep some sticky tires in the trunk though :D

"pure street motor (well, maybe 2 or 3 visits to the strip per year)"

I hade 665ft/lbs in my old streetcruiser. Ovalport 468cui. Nice fun ride. But fries tires @ street to easy. $$$ in tires. ;) And not as fast as you want.

My BM 2400 also lasted for years. It finally broke after a few hundred low 12 passes. Probably my fault.....
Just be careful coming out of the water.
If you never run slicks, no worries.
Ron

Hmmmm, something must be weird about a 454/4.375" block/crank combo. I can't be the only one who has considered this before....no one with experience?
I am beginning to feel hesitant in proceeding with this idea now. :confused:

Maybe the question should be "just how large a crank can be dropped into a 454 block"?

Speed-o-motive offers this 454/510 BBC rotating assembly so it must be feasible.

Charles

The 8.1(496) uses a 4.375 crank and 4.250 bore from the factory. Granted, its in a later block, not a gen IV, but like I said before, as little as had to be removed to clearance for the 4.250 strokes, I can't imagine how an extra .125 stroke would cause any problems. I'm trying to talk a local guy out of 502 block he has setting around, and if I can get it, I am planning on using a 4.375 in it. Once you get started building strokers, it hard to want to go back to building "little" 454s. smile.gif

In my 74 454, the 4.25 stroke crank fit with no clearancing at all, I beam rods 6.385 were used also.

pdq67 had something thought out w/ a 4.375 crank I believe, maybe he'll chime in here.
Mitch