I finally got my magnum heads/new cam broken in on my '84 318 (thanks for the help btw) but I'm running lean. Anyone re-jetted the Holley 2280 or know what the stock jets are? I think that where the problem is anyway...

No vacuum leaks I can find. Timing is about 12° BTDC if the rubber hasnt slipped.

If your talking about the dinky factory 2bbl, noboby I know of makes jets/pins for 'em. Drilling out the jets is one way, reducing the air bleeds is the other.The air bleeds are tricky to calibrate though.
Either way it's trial and error. I saw a Super Stock 273 racer in a magazine with the factory 2bbl BDS. Seems like The Carb Shop done his.I thinkthey drilled it for Holley jets,among other things. The little 273 was crankin 13s in a wagon if I remember right.
A factoryQuadrajet set up would be legal,and run better to boot. Don't much like the Thermoquads myself.

Bah I thought for sure Holley would have some parts to swap in.

I havent been able to find a used iron 4bbl intake anywhere and a new Edelbrock is $220 so I'm trying to put a few miles on the current setup and make sure nothing goes catastrophically wrong before I put more money in it. I'll eventually get a 4bbl on there though.

Glad to see you got it fired up. Sound pretty sweet?

i hate dealing with carbs probably because that is an area im not experienced in...i rebuilt mine to find out later i couldve replaced it for 50 bucks more..here is a link that may help ya find more info on your carb.....good luck.
http://www.guaranteedcarbs.com/index.html

ORIGINAL: lugnuts
Glad to see you got it fired up. Sound pretty sweet?


It doesnt sound much different than it did before; same carb, intake, exhaust, etc. Lopes a bit more at idle. Throttle response feels better than it did. Needs more carb/intake though I'm sure of it and dual exhaust whenever I have the spare change.

ORIGINAL: javatman
i hate dealing with carbs probably because that is an area im not experienced in...i rebuilt mine to find out later i couldve replaced it for 50 bucks more..here is a link that may help ya find more info on your carb.....good luck.
http://www.guaranteedcarbs.com/index.html


I rebuilt mine a few months ago before doing any head/cam work. Unless I forgot a check ball or something it should be good as new. Nice link though.

I've been looking around online for some used 4bbl parts. If I can grab a thermoquad & intake for around $100 I might just do it. I'm kinda scared of used plastic bodied carbs though. What model/year used Q-jets? (Edit) nvm, Looks like 85-88

How'd you mate the stock intake to the magnum heads? Or didyou?

arg. you made the la to magnum conversion w/o putting together a little FAQ with pictures? any one of us would love to see some shots of how that all goes together

ORIGINAL: lugnuts
How'd you mate the stock intake to the magnum heads? Or didyou?


I made a jig similar to the one found here: http://www.bigblockranger.com/Jig.html
Cost me about $20 in materials including the drill bit & tap. Worked great.

ORIGINAL: nemesis_SS
arg. you made the la to magnum conversion w/o putting together a little FAQ with pictures? any one of us would love to see some shots of how that all goes together


I had considered it but I got lazy. It really is a simple, straight-forward swap though. The only real "mods" I did were the LA intake bolt holes and filing some casting flash around the pushrods. Everything else was bolt-up. The whole project so far cost under $600 including oil, filters, lubes, jig, files, engine paint, gaskets, spark plugs, cam & lifters, pushrods, headbolts, heads w/ cleaning & surfacing & checking, double roller timing set, and shipping costs. More to come, but it hasn't shredded my wallet just yet.

Pretty cool. I never was a big fan of the Thermo-wad carbs either. When they're right,they're right,if not they can be a pain. The Q-jet was alot more dependable. If you can't locate a Mopar Q-jet maybe get a 305/350 Chevy,or a 307/350 Olds, and a junk T-quad. Grind the bradding off the end of the shaft
that holds the T-quad throttle lever to the shaft,and install it on the Q-jet by tack welding it. Gives you the Mopar kick down etc. I've done this before.
You still have to deal with the 2bbl/4bbl linkage differences etc, but it works OK.I'm not sure about choke well/linkage clearance with the Q-jet,been 15 yrs since I did this.
[They say poor folks have poor ways,and I'm damn sure poor]

If you decide to do the thermoquad swap,make sure you get a spread bore intake or the tq won`t fit. the bolt pattern is different and the back butterflies on the tq are much bigger than the regular manifold.Up until 1970 the 340 came with a carter avs carburetor but in 71 they came with a thermoquad.Back in the day I replaced an eldebrock ld 340 intake and a 750 cfm holley with a stock dual plane 71 intake and a 850? cfm thermoquad off a dodge motorhome and was amazed at the difference it made.I always thought the tq was great for the street because the primarys are small and dont waste fuel when you`re just cruising but when you step into the secondarys---hello! Carter used to make what they called a strip kit for the tq which was different metering rods but I dont know if you can still get them.Those magnum heads breathe ALOT better than your old stock heads.You need more fuel to feel the gains you`ve made.I think you will be surprised when you feed that thing some fuel.Please keep us informed

Well have you been up the road and back in it yet?

ORIGINAL: bpcarman
If you decide to do the thermoquad swap,make sure you get a spread bore intake or the tq won`t fit.

Thanks for the heads up. Another reason to get a Q-jet I guess :)

ORIGINAL: lugnuts
Well have you been up the road and back in it yet?

I've only babied it around town a bit but it sounds like everything is working like it should. No valvetrain noise. I'm trying to get ahold of those 4bbl parts now and get them installed before I swap out the break-in oil and really get on it. It's just not fair to judge yet with that 2bbl strangling the power. I've got some calls to make next week but it's looking like I'll be getting an '86 4bbl intake and Q-jet needing a rebuild. Another week or 2 and this rig should be on the highway towing my boat to the Lake. Hopefully it does better than it did last time. That pic I'm using as an avatar... that's me broken down on the side of the interstate towing my boat last summer. I had to have the truck and boat towed back home in shame. Needless to say, this truck has a lot to prove.

One thing on the Q-jet rebuild. If you've never done one,be sure to JB Weld the plugs in the bottom of the main body directly under the jets. These are about5/16-3/8' in diameter. They are prone to leaking,and willcause hard starting and oil dilutionafter the truck sets a while because itdrains the bowl. You gotta cuss and crank till it gets fuel again. Have ever adjusted the secondary air doors on a Q-jet?
If your luck's like mine,the boat'll quit next.[:@]

PLEASE OH PLEASE don`t put a qjet on a Mopar.They don`t belong there and it`s like a crime against nature.I know it`s your truck I just thought maybe you needed my unsolicited opinion.By the way qjets are spread bore carbs too.

And I blame the boat for the truck breaking down.bad boat

ORIGINAL: bpcarman
PLEASE OH PLEASE don`t put a qjet on a Mopar.They don`t belong there and it`s like a crime against nature.I know it`s your truck I just thought maybe you needed my unsolicited opinion.By the way qjets are spread bore carbs too.

Too late! I've got an '86 intake and carb en route. If it's junk you can say 'I told you so' :)

ORIGINAL: lugnuts
One thing on the Q-jet rebuild. If you've never done one,be sure to JB Weld the plugs in the bottom of the main body directly under the jets.

Will do.