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age old carb debate sorry guys

westirmax

Contributing Member
Hello all:

carb choices for aging chrysler 360's

I know this has been asked and answered several times. I'm frustrated with my current 360's and the quadrajets, I've rebuilt them and I'm still getting poor results, erratic idle, some days rich some days lean. Just cant get both engines to run the same, one engine seems to burn much more fuel than the other.

I want an alternative.

i'm looking at the holley 4175 marine. like this because its a spread bore like the quads and I dont really have the height to add an adapter plate. At $600 clams a piece I want them to work better than the quads.

The other choice is the edelbrock 1409's. Again a square bore to spread bore plate is recommended, can someone confirm that its "required". A bit cheaper but the height might be an issue, unless i can forego the adapter.

both carbs require me to setup electric chokes but this is not an issue. would be better in the long run anyway.

final choice is to have the quads done by a professional shop and have them done front to back including re-bush the throttle shafts.

Has anyone done the swaps i'm thinking of, if so what did you run into as far as plumbing or fitting the throttle cables.

Greg-
 
the 1409's are square bore so you have to use an adapter or find a square bore manifold (maybe only viable option if vertical clearance is limited)...

Personally, I think the q-jets will give you much better efficiency if the are properly setup.....if you do replace them, I'd be happy to take the cores off your hands.
 
I prefer the Holley which I had on a spread bore Edelbrock manifold and it seemed OK. There was some grumbling about
the 1409's after they were on awhile as far as getting them to keep in tune. Search the threads, our resident expert
on those FastJeff must've sold his house boat with twin 360's because he's no longer on here....
 
He was a big fan of the 1409 but then he started to complain about something...???
That's what makes me remember there was some discontentment with them. I know
there were problems starting them after they sat awhile or got hot...???
Not sure anymore but the Holley I have fire's up on the 1st crank even after
getting it out of storage. Always amazes me actually..... Been wanting to try the
Q-Jet though but why bother....???
 
Thanks Guys- I may try a Holley 4175. see if i like it, but that's a $600 gamble. I've watched a few videos and its a proven performer as far as the street goes, very adjustable. the electric chokes are a bit more stable i'd assume. vacuum secondaries is new to me, but the spring based adjustment sounds workable. I hardly every accelerate hard enough to open the secondaries. I'm curious as to how close the fuel inlet is relative to a quad-j, or if the plumbing is going to be a headache, right now I have hard fuel line from the fuel pump to the q-jet.

Would be great if someone could check-in that's done this swap already.

Greg-
 
Have you done complete mechanical inspection of both engines? Check for true TDC on number 1 cylinder? Check timing chain for slop? What are the compression numbers? Map out the advance curve for both engines? Fuel is always the last thing once you confirm the engines are mechanically sound.
 
ME.com sells a flexible rated fuel line that makes the plumbing portion a breeze....there have been a few posting here in recent years on a few different engines....suggest using the search engine if interested...
 
............ Check for true TDC on number 1 cylinder? Check timing chain for slop? .............

Old, tired balancers can spin. As you verify #1 at TDC, also verify the balancer outer ring is still lining up. Mark TDC on the outer ring and the inner for future reference.
Example...
BalancerMark.jpg
 
A call to holley revealed the carb has a PCV port( which I'll need) and also both 7/8"-20 and 5/16"-18 options for fuel inlet. in studying the layout of the 4175 I may be able to not have any fuel connection issues. Phone tech recommended the black spring for the secondaries as it has the max pressure thus keeping them closed as long as possible( best fuel economy) but said it should work great right out of the box( like I expected to hear something else).

Greg-
 
I have a Quadrajet removed from a new 360 in 1990. Bought on closeout and installed into a conversion van. Motor was still on shipping pallet when carb and all marine gear was removed. Never run. Stored in heated garage. Asking $250 plus postage.
 
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