340 horsepower rating

[jimharvard]

I'm just finishing my 340 4 speed 68 formula s fastback resto. This car is a replacement for the "new" 68 formula s I had in high school in 1969.

My original barracuda had fenderwell hooker headers, 3.91 posi, 750 DP holley, and an edelebroc alluminum "high rise" manifold. It was a consistent mid to high 12 second car with open headers and slicks. The barracuda I'm building now has the same components except for "under chassis" hooker headers. These cars are just worth too much money now to take a reciprocating saw to the fenderwells.

Do any of you racer types know if a 340 produces less horsepower with underchassis headers vers fenderwell ones? Also, I'm putting an "X" style exhaust system from the headers back with low restriction mufflers. I'd like to go to the larger 3" pipes rather than the 2 1/2" original pipes. Is there any performance loss by going to the larger exhaust pipes?

Any info or opinions will be greately appreciated.

jim coster, pittsburgh, pa
aka "jimharvard" at FABO

 

[1968FormulaS340]

If you are looking for 12s, under chassis headers and 2.5" exhaust will get you there and beyond.

Only the most serious, stock stroke, small blocks need 3" exhaust. More than likely the only thing you will get from 3" is a lighter wallet and possibly a little less grunt on the low end.

 

[AdamR]

The fenderwell headers would possibly make more torque because of the longer tubes. I ran 3" exhaust on my 69 Barracuda 340, I wouldnt say the loss of torque was noticeable. Did cost me anymore to do and It didnt seem louder then the 2.5" The tone seemed deeper to me though.

 

[OldmanRick]

My buddies 70' E body picked up over a tenth and a mph doing this same swap. I believe the fenderwell's were 1 3/4" and the under chassis were 1 7/8".....iirc.

I can't speak to the exhaust, as they were open only on both setups. Also, the car had a 5.13 gear & 28" tires, so bottom end torque wasn't much of a issue.

My opinion is you'll lose nothing, and will probably gain some. Good luck, I love the old school style build. :thumleft:

 

[jimharvard]

thanks to all you guys for the thoughts...

i bought my first 340 4 speed formula s in the summer of 1970 from "Gabby", a plymouth dealership mechanic at Glen Dale Motors in Glen Dale, W.Va. Gabby bought this car new and did a number of performance mods to the car including putting in the hooker fenderwell headers. back then, no one cared about sawing out fenderwells of "new" cudas. i can't imagine taking a sawsall to an original cuda fenderwell now.

as to an "old school build" ... after high school, i ran a body shop from 73 to 75. lots of repairs were "old school" back then. as such, my current cuda had all the small rust holes repaired with LEAD and i gunned down the body with very nice ACRYLIC LAQUER turbine bronze paint. the only place i was able to find this paint now was from TCP Global in San Diego, Ca. (of all places!!). Every pannel on this car was shot with "slow" thinner then after a couple of days, sanded with 2000-2500 wet paper then "buffed" with a random orbital buffer. no H2O paint on my 45 year old cuda! I have nothing against the modern restos but I have to say, mopars NEVER looked like they do with present materials when they rolled off the car carriers in 1968. the turbine bronze on my 68 cuda doesn't have anywhere the depth or shin as lots of resto cars i've seen at car shows. however, my cuda DOES look like it did in 1968. and, my car is 99% original. i literally "reconditioned" and reinstalled every nut and bolt and trim piece that was on the car. there are a few small parts that i couldn't save and had to replace but you could count these parts on one hand.

i would call my car a "survivor restoration" and it has lots of imperfections all over it. the underneath was even UNDERCOATED - just like i did to my first 68 back in 1970 to protect it from the w.va. snow and salt on the roads. now when i look at this car, and then look at myself in the inside rear view mirror right before i fire this baby up, i see two great items that have aged a bit but still a lot of fun to be around.
jim coster, pittsburgh, pa

 

[AdamR]

we need pictures !

 

[replicaracer43]

we need pictures !

x2

 

[CHEATHAM]

I had the headman hussler race 2in prim 3 1/2 coll. under chassi headers on my 340 duster, they worked great, 340s to me seem to always run better with unusally bigger carbs, headers and some time cams, in a a-body I think a fenderwell has fewer sharp bends exiting the port which will make better power.

 

[jimharvard]

here's some pics...

this car came from oregon and the "mopar" fans out there decided "plumb crazy" was the way to go ... i don't think that color looks good on the 67-69 cudas...


now with about 1850 hours plus the "cover car" from the front of the 1968 barracuda sales' brochure is about 80% finished....

"restored" original s emblem, those "holy grail" red fender liners in the background waiting for installation, restored "gills", newly installed weather stripping....

 

[Abodybomber]

I love, "Turbine Bronze"! Yes,the TCP Global lacquer ,shoots nice. Called.them,said the older PPG/Ditzsler pigments.

 

[jimharvard]

i have had very good luck with TCP Global in san diego, ca. all total, i bought 3 gallons of lacquer paint and three gallons of slow thinner from them. their color quality seemed spot on but i did mix all three gallons together just to be safe. the paint went on great although their "slow" thinner is really not slow enough for temps above 80 degrees.

here's a bit of news that floored me when i first saw it in TCP's calalogue - especially when i think of how much paint cost when i had my body shop in 1975. TCP has "factory mix" acrylic enamel from PPG in all the old plymouth colors. as you purists in FABO land will know, chrysler used acrylic enamel on their cars through the 60's and 70's while GM used acrylic laquer. the price for TCP's "factory mixed" PPG enamel? would you believe $996.00 per gallon!!! my my, how the world has changed in 40 years!!

while i really wanted to do my 68 cuda as original as possible, i just could not get my mind around $1000 a gallon for paint. i did find a NAPA dealer in bridgeport, ohio who still mixes acrylic enamel but they wanted $525.00 a gallon. so i went with TCP's laquer at $227.00 a gallon. the look of laquer is very close to the look of acrylic enamel of the 1960's in my opinion, laquer is still the best for the "back yard" resto project. it drys fast and mistakes can be fixed easily in a day. the bad news is though that EVERY imperfection that you miss in preping the panels will show up and the wet sanding and buffing is a bear. but it is hard to beat a glass smouth laquer painted panel with a deep coat of wax.

 

[AdamR]

A few years ago when my Dart was painted it was $800 for 3 liters of base. My Duster is getting painted this week in Diamont, I didnt bother asking yet. Dont want to know.

 

[Abodybomber]

Harvard,paint's so insane nowadays.A buddy owned a Turbine Bronze 67 Cuda. Wears 90% ,of it's original paint. You're so damn close,don't sweat it.As for the Napa pricing,I sure hope that was the Tec Base AcrylicEnamel. The Crossfire gallon cost me $ 147.00 ,six years ago. Damn.