Need Help! 360 first rebuild need to check my facts!

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Jimmy

Jimmy

74 Swinger
Joined
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Ok so I'm building this for my swinger, it is for the strip, but street legals so I'm not looking for the most expensive answers, just the most practical.
Here's what I (think I) know, and what I have.

1980 360 cop engine:
4006830
BORE 4.000"
STROKE 4.000"
ROD LENGTH 6.123"
MIN. CLEARANCE .0015"
COMP. HT. 1.465"
PIN DIAMETER .9842"
CRANK CL TO DECK 9.599"
WT.PISTON/PIN 483/132g

J Heads:
596
Intake 1.88
Exhaust 1.60
66cc
open chamber

Carb:
9811
Carter Competition
800cfm
bore 1-3/8

Headers:
Hooker competition

Stock rebuild kit:
Bearings, seals, rings, push rods, oil pump, frost caps- all stock and came with it so I'm not attached.

Here's where it gets confusing

I kinda wanna keep the heads but don't mind changing the components unless it's just way cheaper and easier to pick up magnums and the gains will be significant without a $600 cam

Intake manifold:
None and undecided, Air gab maybe? spread? single plane? dual plane? Seing as how the Carb is a Carter I should prbly stick with Edelbrock.

Overbore:
Should I? Would this be productive considering it's the compression I want to raise?

Nitrous:
Yes
Amount = I don't know, how much can it take?

Cam:
machine stock or:
?????

about all for now, need to answer these before I can decide on pistons and such,

Wife is yelling have to go, any clarification just ask and I'll try,

Thanks!
 
Okay here's what I'm in the middle of, a simple pump gas 420hp 360 with stock block, crank, 340 rods, stock X heads cleaned up ports.
SRP forged pistons, 10.2:1 CR
Comp solid flat tappet cam XS274, .501/.511 (it's about all stock heads clear without machin work I can't afford at the moment)
High rise dual plane Weiand intake, old swap meet piece #7507(?)
MSD ignition and distributor
hooker headers, the regular primary tubes, not huge ones
also using a milodon lifter valley baffle to help cool intake i.e. fuel
proform 750 DP carb, it's a manual steering 74 duster, full interior street car @ about 2900lbs w/o 200lb driver
727 with 10" 3-3500 converter and manual valve body. Looking for low 12's to maybe high 11's this year then next year hit it with 125hp kit. Keepin it simple and gettin results, the name of the game 8)
 
Stock crank is 3.58", not 4".

As for the rest, I'll let guys much more knowledgable than myself chime in. However I did a magnum swap on my heads and it was easy, with the exception of ordering custom length pushrods so that I could use a flat tappet cam with the stock magnum rockers.
 
Jimmy said:
Ok so I'm building this for my swinger, it is for the strip, but street legals so I'm not looking for the most expensive answers, just the most practical.
Here's what I (think I) know, and what I have.
Click to expand...


It sounds like you need a book, "How to rebuild and How to hot rod your small block MoPar"
By your description, your all over the place.

I'll try and answer somethings, but I think they'll create more questions and confusment.

I kinda wanna keep the heads but don't mind changing the components unless it's just way cheaper and easier to pick up magnums and the gains will be significant without a $600 cam
Click to expand...
Talk to OU812 on Magnum heads and the combo your building. He's the best bet on this topic right now. As is, a 400+ cube engine will need a bit of porting on those heads including bigger intake valves.

Also, use super comp headers, 1-3/4 min, 1-7/8 for racing. The reg. comp. headers are street and light race, OR, good for paper weights according to what you want to do.

Intake manifold:
None and undecided, Air gab maybe? spread? single plane? dual plane? Seing as how the Carb is a Carter I should prbly stick with Edelbrock.
Click to expand...

If you plan on useing a T-Q carb, I'd go with the larger primary carb @ 1.50 inchs and use a MoPar M1 single plane intake.

Overbore:
Should I? Would this be productive considering it's the compression I want to raise?
Click to expand...
If you need to overbore the block, then do so. Productive? How about no choice in the issue if it needs it.

Nitrous:
Yes
Amount = I don't know, how much can it take?
Click to expand...

Have your engine builder know this or make sure you gap the rings correctly or they'll break and destroy the engine.

Cam:
machine stock or:
?????
Click to expand...

IDk what a machine stock cam is, but cam choice is dependent on the RPM you want to run in, (Duration) and how well the heads flow (Lift)
Also stall converter, car weight and gear ratio/tire size.

You can use a big Hyd. cam, but you will be leaving alotta HP on the shelf. A mechanical cam would be better, but also require adjustable rockers which cost alot. But worth every dollor spent on gaining a good bit more HP and torque.
 
rumblefish360 said:
Also, use super comp headers, 1-3/4 min, 1-7/8 for racing. The reg. comp. headers are street and light race, OR, good for paper weights according to what you want to do.
Click to expand...

Rumble,

Do those headers have any clearance issues that you know about? Do they lay sparks like a magnesium block on a low rider? haaaaa
 
Well, my Mad Dart freind, I went with this in the back of my head. I do beileve there cheaper than tti's and will have more ceiling performance than ethier header.
Ok so I'm building this for my swinger, it is for the strip, but street legals
Click to expand...
Super Comps are very low for the A body cars, style dependent, you can have 1 tube go down infront of the K frame by the front of the engine on the drivers side.

Unless you have tti's or Dougs headers, your scraping the ground.

Since it's track driven............
 
you can get by with the 1 5/8 headers on a 408, combo,=cam/rpm/carb/intake/head flow ratio, makes the diff. And just run at least a 2 1/2 pipes, preferably 3''

the heads can be ported to flow well enough for 500hp if done by someone with experience in porting the J/early LA head.
go with a 2.02 int valve and a 1.65 exhaust, see if you can get them in 11/32 stem diameter and make sure the stem height is cut after mounting rockers and checking geometry
though some will argue/debate going 2.05/1.60, I say the exhaust could use it more.
With any idea of good port shape and how much room for it there is, you can get 260's-280cfm no problem when full porting the early J,X,U,O etc...
rhs heads are a good bang for the buck head that'll bolt on and make 500hp with enough cam as well...

preference will guide you, for the diff between 2 is min in ways and just enough [for me at least] in others.

JMO
 
"Rumblefish360" Well, my Mad Dart freind, I went with this in the back of mu head. I do beileve there cheaper than tti's and will have more ceiling performance than ethier header.
Click to expand...

How about these headers then going to a reducer 2 1/2 " to 3" to 3" X Pipe??
These are pretty inexpensive, then hitting the ground shouldn't be an issue.

http://www.jegs.com/i/Hedman/500/78500/10002/-1

What you think? Just looking for other alternative's to the $700.00 Header, and could possibly work well on a 360?
 
I'm not a fan of shorty headers unless need dictates there useage.
Also, pipe size is dependent of HP leves to start with and then intended purposes there after. Normally, I'll stay with a single pipe size though out the system.
 
If you don’t mind spraying it I have a combo that could plop you right into the low 11’s or high 10’s that is relatively simple and somewhat cheap (I don’t know how much you want to spend so….here it is). This was my old combo that I ran for about 7 years.

360, stock crank and rods, ARP head/main studs and rod bolts, SRP forged pistons, 10.7:1 comp, OOTB Edelbrock heads, Mopar performance 292/.509 hydraulic cam,
Air-gap, 750dp, 1 ¾ headman headers, 727, 3000 stall, 4.10 gear, spool, 28x11.5 Hoosier QTP,
NOS cheater kit, 150-180 shot , 3250lbs with driver
When I lived in Colorado, this made my Cuda run 11.1’s all day long (which would probably be mid 10’s at lower altitude) .

Basically, if you are going to spray it, all you need is a solid bottom end and some decent flowing heads…and a good ignition and fuel system….ah crap…I just reread this and it doesn’t look very cheap anymore…Sorry....but since I already typed it, I'll leave it as food for thought. Anyway, that’s my 2 cents.
 
Great info everyone, thank you! I'm not sure where I got that stroke from.....

Ha Flyfish, I got excited for a minute. yes.. yes.... ok ..... sounds good..... damn damn damn! Seems like every combo eventually ends the same way but I like your thinking. Basically the car has had most of the bottom end done by the previous owner, he started bottom up and then got distracted by a Charger.
It has a 8 3/4 posi (sure grip?) with 3.73 gearing, 727 trans, disk breaks in the front, I have to check out the rest of the drive train when I get it in the air but I am rebuilding it with a 318 in it and building the 360 separately.
Im just going to the races to have some fun plus having a rolling billboard for my shop is a write off so win win, basically no competition, just slips, and I would crap myself for anything in the area of 12's or even 13's. The weight is about 3000 lbs as it sits so I don't think I need 600hp to get there, although it would be nice.

Thanks for your help Rumblefish, I'm downloading the sheppard book in pdf as I type and Ill print it out when I get to work, good $15 investment.

Clarification:

I think the headers are super comp just didn't say so in the description but they are under the super comp heading
5205HKR
67–69 Barracuda/Dart/Swinger, 70–75 Dart/Swinger/Demon/ Duster/Valliant/Aspen/Diplomat/Volare(A Bodies): 383–440
Full Length Tube 1.875" x 40", Collector Size 3.5" O.D., Collector Length 10", Port Shape: Same As Port, Black High Temp Paint

So will these have clearance issues? How can I prevent that? a full tti exhaust? that's probably doable.

I already have the QT, I found it 20 years new in box from CL and picked it up for $200 and was fairly happy with the purchase so if I can build with this carb in mind that would be great.

I'm thinking the hardest thing is not doing the wrong thing first, so if I seem like I have no idea what I'm talking about that's because I don't so I'm all ears, just onna budget. Cost wont stop me but it will slow me down.

and just to keep it realistic lets put my ideal at 350-400hp if I can make it to the strip this season I can put more in next summer to get it into the 500 area.
 
So will these have clearance issues? How can I prevent that?
Click to expand...

Answer; ---> http://www.forabodiesonly.com/mopar/showpost.php?p=918948&postcount=7

Flyfish has a basic combo with little added on. OK, it gets expensive, but speed costs, bottom line. It's the extras with the No2 that tally up quick.

I had the nearly the exact combo flyfish listed except in a 4spd '73 Cuda and no laffin gas. The short block was a MP create short block and tires were 27 inchs.
While a bit heavier than the A body, it would still move real well. (Best results with less than 5 gallons of gas...Ha ha ha ha ha)

Create short block, $1200
Edel heads and intake, $1500
Headers $300 - (Yea, gottem awhile ago)
Carb $200 (Yep, had this awhile too)
Straight exhaust pipe and 2 mufflers, $100

*Total, $3300* Mid 12's OOTB & Low 12's after tune. high 11's after a good diet program for your A body.

(Approx cost or so, converter and gear not included, small stuff not included, gaskets, sealent, etc.... LOL You know the drill.)
 
sorry to beat a dead horse but a full TTI will fix the problem or do I need a new header as well?

For what I'm talking about should I skip the spray? will the 3.73 gearing do it till next season? This is my first, never dragged before so I'm thinking baby steps, but I also don't want to fall flat on my face. The build you propose sounds reasonable, but my time machine is in the shop :-D
As racers should I just stick with the 318 on nitrous this season to get a feel for it and start stockpiling parts for next season? that would give me a much better budget for the 360.
 
5205 hookers are Big Block fenderwell pieces.

there are a couple of Super Comp headers for SB's, 5204 is one set in 1 3/4 tube. There is also or was a set in 1 5/8", not worth the money for the 1 5/8.

Only two full length headers fit well on these cars, Dougs and TTI. I like Dougs because they cost less and work well.

I've never tried to install any shorties on an A body. I've heard they tend to have their own issues with fit.
 
crackedback said:
5205 hookers are Big Block fenderwell pieces.

there are a couple of Super Comp headers for SB's, 5204 is one set in 1 3/4 tube. There is also or was a set in 1 5/8", not worth the money for the 1 5/8.

Only two full length headers fit well on these cars, Dougs and TTI. I like Dougs because they cost less and work well.

I've never tried to install any shorties on an A body. I've heard they tend to have their own issues with fit.
Click to expand...
that would make sense, they came with the engine and it came out of a charger, should have paid more attention to the 383-440. ok so cl those and pick up some Dougs, perfect thanks.
 
Jimmy said:
sorry to beat a dead horse but a full TTI will fix the problem or do I need a new header as well?

For what I'm talking about should I skip the spray? will the 3.73 gearing do it till next season? This is my first, never dragged before so I'm thinking baby steps, but I also don't want to fall flat on my face. The build you propose sounds reasonable, but my time machine is in the shop :-D
As racers should I just stick with the 318 on nitrous this season to get a feel for it and start stockpiling parts for next season? that would give me a much better budget for the 360.
Click to expand...

If you have not done so yet, just take the car to the track the way it is. It may not be the fastest thing around but you'll gain tons of experience and you will have a baseline to compare future improvements to. With or withour nitrous I think it'd be a good idea. And don't forget when you add up the cost of your new bullet that the guy at the machine shop isn't going to work on your motor because of how much he loves his career lol they gotta eat too. Also without forged pistons and an auxillary fuel pump/system you really shouldn't spray over 150hp, or if you aren't dead on with the tune up keep it to 125hp just to be safe. . . and better chance of keeping the guts inside the oil pan :-D
 
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