Stock 1975 Dodge Coronet. Mopar guys.
 

What engine in a 1975 Coronet 2 door would make for a good(consistent/competitive) combination in NHRA stock? 318 or 400? Can anybody recall seeing a 1975 Coronet being raced in Stock? Any ideas or information would be appreciated. Thank you.

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

You might be able to outfit a 2 door as a Road Runner also.

Register and log in to research the options here:.

http://www.classracerinfo.com/

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

Convert to 78 = just some trim change Grille etc.

318/230
360/276

These are the best factors for this body

We race both these combos with success

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

Interesting. Just for my own understanding why wouldn't the 190hp or 235 hp 400 engines be good as a combination? Is it because they, if I'm reading the NHRA classification correctly, have been factored to 310hp and 320hp respectively. Is the low compression that much of a hindrance? What about the 1975 360 190hp? Good combination even if its been factored to 276hp?

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

The 400 in our 74 Ply. Sat. is 294 iron 296 Aluminum = same engine at 310 or 320 - You would not stand a chance against us.


The 360 / 190 if a four barrel would be OK.

The 318 to be a four barrel has to be 78 up.

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

Thank you for taking time to answer my questions GTX John. It is appreciated since I am trying to learn and you have the knowledge gained from hard work and experience. If you have the time could you explain why the 400 combination works in a 1974 Plymouth but may not be so good in a 1975 Dodge. Trying to learn the ins and outs. Thank you.

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

Different Horsepower factors for similar engines in different year
cars.


My 73 400/Aluminum head = 296
Your 75 400/alum. head = 320

I/SA 12 LBs. per HP
Means your similar engine would have to weigh 290 Lbs
more than my car in the same class - An almost impossible
difference in weight to overcome give everything else is the same!

Much easier to change year of car when it is just grille/taillights
would give you a better factor or combo to work with!

The 78 318/230 is a great combo= we held the National Record and
many class wins including Indy before my son got bored with it and
decide to go faster!

The 78 360 started out at 270 and was a class winner and fast.
Eventually the Wagon was factored to 289 while the sedan was 270
making class impossible for us. Now all the 78 360 are at 289 with
either big cam or our old small cam version. The big cam is still
OK but no longer a killer combo.

Half the battle in Stock and Superstock is selecting the most competitive combo
out of some many possible choices.

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^This!^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

It doesn't make sense, so don't be confused. NHRA doesn't make sense. There is not much logic.

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

Thank you everybody for the replies and insight. As this would be my first experience with NHRA stock along with a couple of friends and we have a 1975 Coronet with a 400 it seems that if we went this route it would be a learning experience and wouldn't be competitive on a national level and/or in a heads up situation, not that we're expecting that. Might it be at least a consistent combination with either the 400 or 360?

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

Consistency depends on how you build it, tune it and know what to expect from it under different conditions. "Predictability" is the key. Weather stations/predictors can help.

As for competitiveness, if you get the previously mentioned factors figured out AND you can at least run under the index in the worst conditions and have decent reaction times, you are, for the most part, competitive! Class eliminations or the occasional heads-up in regular eliminations are another story. That's where finding the most advantageous combo and a lot of work and resources ($$$) to be among the fastest comes into play. A specific class with the least amount of cars competing in it can be helpful in avoiding heads-up runs while you make progress on yours. You can move up or down one class from your "natural" class with weight.

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

Thank you for the insight Myron. A couple general questions. The technical specs for acceptable carburetors shows Carter Thermoquad
9008,9054, 90064 and 9097. Just to clarify these are the numbers that have to be stamped somewhere onto the carb correct? Engine blocks?
Any year 400 block is acceptable?

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

Any year block and any TQ with the same venturi & throttle bores. No machining and the choke parts stay in place.

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

Thank you for the replies. West coast guy here. Who are the mopar guys to deal with for engine machining/building? Ive heard different names over the years just not sure who is still around for stock engine builds. 727 OR 904 behind a 400ci stocker? 8 3/4 or dana? Thank you.

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

hi,
I am building a 75 cordoba 400 TQ L M stk. just for fun hope to qualify 12.40's

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

I have a 75 Coronet Brougham that was bought new by my Brother to race in Stock in 75. It was raced from 75 to 87 in N & O/SA . It started as a E58 big cam 360 and got factored, so he ran it as a E56 small cam car. It went high 12:20's in late 1987 before being parked. I raced a E56 74 Charger in Stock until 1997 & that went some 12:0's in 97 in L/SA.. We set 7 NHRA records with both cars before retiring. I am currently putting the 75 Coronet back together and as said earlier it is rated 276 HP, and is a L, M, N car. The car never broke the 8.25 rear, just one stock axle in early years. It did have a Strange spool and axles, but will probably require upgrade as it is a fairly week rear and gears aren't available.

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

The 360 @ 276(Small Cam) is a great combo =
We just finished one.
If properly built it is a 1.0+ Player!!

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

GTX John, my Charger went -97 under (13.00 index then) in 1997 before being retired @ 3950 lbs. It was rated at 280HP then. In our 25 years of racing that combination it was 270, 275, and 280HP. I ran K, L, & M, at various times with the Charger.

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

Very cool to hear some of the history of these forgotten mopars. Tom was your brother's car in Super Stock and Drag Illustrated? I bought my Coronet because I saw a picture of one racing in stock from a 1975 issue. I kind of liked the body style. What transmissions and rear ends do you guys run behind the 318/360/400 combos?

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

Yes the car is the one pictured in the 1976 Super Stock magazine after he set the N/SA record at Suffolk in October 1975. It is also pictured in the Direct Connection Catalog from 1978. Picture was from Indy. We ran a 4:88 in the 8.25 rear in his car with a low gear 904 Trans

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

Who are the go-to guys for engine machining, transmission building, etc?

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

Our 400 Mopar short blocks was built by Gregg Luneauk at Tri City
Performance in Vista Cal. It is 1 Second ++ when we need it to be!

Must run 727 as 904 will not bolt in without Illegal Adapter.
Pro Trans in Waco Texas did the Transmission.

We break a lot of very good 8 3/4 in that heavy a car. 73 Roadrunner @ 3800 Lbs

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

Thanks for all the replies. John what rear gear do you run?

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

Believe it or not: 4.56 Dana with 94 Cir Goodyear Radial
Shift @ 5900 to 6000 RPM
Not a High RPM Combo!

Gregg Luneauk does our Short Block
Brad Van Lant does our heads

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

Would a 383 block bored .060 over be legal.

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

Yes, for a 383.

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

You might want to think about a filled 400 block as well.

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

What's the RPMs through the traps?????

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

6600 @ 119

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

A dana 60 for the back. Before you machine or choose an engine combination look at ring availability. The 360 with the factory 4.00" bore will have a better selection of piston rings than the 4.340 bore of the 400. Dont forget to look at rod selection on the approved list and if they are available.
Just some thoughts.

Re: Stock 1975 Dodge Coronet. Mopar guys.
 

Our 400 is .040 Over = 4.38

We get "RaceRings" from Gregg Luneauk
at TriCity Perf.

Very Pleased and Grateful for them particularly when
we are racing Heads Up!