I'm thinking about replacing my carbs. I removed the original flat tops and de-smogged when I tore the car down. I was planning to use the set of round tops that I bought on eBay and rebuilt. I took them apart completely, rebuilt both and cleaned everything very well. The piston and needle assemblies move freely, and drop with a nice thud.

I have the car back together (figured out my electrical problem - bad male terminal at the resistor), and close to running, but I think the carbs are a problem. The car runs (barely) very lean, then I adjust the float bowl or mixture screw, and its blowing gas back out of the carb. I don't like the way they're working, and I'm thinking it might make sense to go with a new set from ZTherapy. I've taken the work this far, and I don't think it makes sense to rely on 35 yr. old carbs, and it seems like new ones would be $700 well spent.

My question is, are the ZTherapy round tops the best option for my motor and my driving plans, in the $700 - $800 price range. The car is a 73 240Z, original low miles L24. The head was removed and reconditioned, but not altered. Stock cam, MSA header. I'm not a racer at all, so dependability, and driveability at normal speeds is what I care most about. Although I'd like the car to have some jump off the line.

IMHO, ZT carbies are the way to go. you said you aren't planning on racing, so triples would be a little overkill (not to mention a bit more fuel)

only other option I could see would be triple 40s; but again, i think that might be overkill for your purposes

Stock head, stock cam: I'd vote against triples. As far as your SU's go here some advice that Bruce gave another member that was having lean problems.

Try lowering both fuel nozzles a half turn and see what happens. If that improves the situation, try another quarter or half.

ZTherapy, your car will thank you every time you turn the key.

Will

Round-tops are probably the best choice for your engine. As for ZT vs. what you have now, chances are that the carbs you bought have worn throttle shafts and/or bushings that leak unmetered air into the intake tract. While you may -- with a lot of fiddling -- get them to run semi-acceptably, ZT carbs will work like new. Which was really quite good.

Go with the SUs from ZTherapy, if you want jump off the line, go R200 (3.7 or 3.9) with an LSD.

Another company that you may want to take under consideration is Paltech Micropolishing LLC, great service and fairly rapid turn around. here is the link http://paltech1.com/index.html

Respectfully,

Alex

After trying to get those 35 yr. old. rounds to work right for a week, I finally ordered my new ZTherapy carbs last night! I sent Bruce an email, he called me back a couple hours later, and the whole deal took about 5 minutes. Bruce was great to work with, and I can't wait to get my new SU's. Thanks to everyone for their input, it made the decision to go with ZTherapy very easy.

Without Z-Therapy, life on this planet would cease to exist...

Oh now, cut it out!! Keep this up Steve'll have to start using the sliding door to get into and out of the shop, what with head swelling and all.

Anyway, thanks for the kind thoughts, he tries really hard to take care of his customers.

Got a new set of ZTherapy 3 screws installed onto my 73 DD Saturday.

The ones I took off were ZTherapy rebuilds from 1998 (previous owner's work)

They still looked nice but were leaking vacuum for sure---never could get the mix or the idle right.

The new one's are like night and day!

Really perked the old girl up----don't know if it'll help milage much but drivability and throttle response is definately there! :devious:

I'm one very satisfied customer!! :laugh:

Highly recommended!!!

Jim D.

"Zup"

p.s. The cores are on their way Bruce--I sent them out on Monday. You'll have a chance to look over the previous owner of ZTherapy's work.

They'll help the mileage. Leaking vacuum is like leaking mpg. EFI or carb.