I have a sbc 350 out of a 73 Vette that I put in my 35 ford. I had bought a holley 650 4165 6210 used and rebuilt it only to find that the base plate is messed up, so now I am looking to just pay the money for a new one. But Im curious if there is any real benefit to getting a 650 4165 vs 4150? i read that the main difference is the metering block on the secondary isnt there on the 4165 it just has a fuel transfer tube. is there and thing else thats really different performance wise/ fuel economy wise or is that pretty much all thats different?
4165 is the Holley model number of your carb, that is a spread bore, manual choke double pumper. I don’t know the List Number but you can find that stamped on the choke horn. Being a spread bore it is a replacement for the Rochester Quadrajet. It only has one fuel inlet with a fuel transfer tube to the secondary bowl and it does have a secondary metering block. Model 4150’s have a secondary metering block, but the 4160 carburetors do not. In either case the 4150 or 4160 are known as square bore carburetors and will not bolt on your current intake manifold without an adapter. Edit- I see you asked if there is any benefit to a 4165 compared to a 4150. If your car is relatively light weight, has a stick shift or an automatic with a higher stall converter and a low geared rear end you can make good use of the 4165 double pumper. A single accelerator pump, vacuum secondary 4150 or 4160 could be a better choice for you but you would need a different intake manifold. Could you use a carb adapter? Sure, but the transition to the spread bore intake costs some airflow and efficiency.
Check the carburetor mounting pad on your intake manifold. If spread-bore, and you wish to keep a Holley, then the 4165. If square-bore, then either the 4150 or 4160. You didn't list the option(s), but if the manifold is spread-bore, then either a Rochester Q-Jet or a Carter TQ are other possibilities. DON'T try to use a square-bore->spread-bore adapter! Match the carburetor to the intake manifold! Jon.
mumbler - Do you mean 4160, vs. 4150 ? As noted, a 4165 is a spread bore. The intake manifolds ARE different. A 4160 and 4150 are both square bore carburetors. And no, it really makes no difference whatsoever in the performance of the engine. The 4150 is just easier to change the secondary jets..! Mike
Sorry the intake manifold was originally for the q-jet. It is the spread bore intake manifold 39977771 that the 73 sbc 350s had
If you wish to use a 4150 or 4160 CHANGE the intake manifold! Personally, I would put the intake back on, and either a Q-Jet or TQ. With open hood, neither is as kool to some folks as the Holley; but either will deliver better part throttle, and significantly better fuel economy. Jon.
Why not buy a new base for your 4165 and fix it ? The spreadbore is going to deliver better fuel milage and a bigger kick in the pants when you open it up. You already have the intake and 90% of a carb so just get a new base and not reinvent the wheel here. I had a 4165 on my T at first then put on a regular 650 double pumper, the car was equal in speed but the 4165 was much funner with it's big bores opening up down low.
i was thinking about doing that but all ive been able to find in terms of bases is just used ones that i can pull off old carbs
no i dont mean a 4160 vs 4150 ive been trying to compare the 4165 to the 4150 to find out which is better or if they would operate essentially the same on that intake. im not going to change the intake.
I had a 4165 on a 57 Chevy a few years ago, and I ended up getting rid of it. Reason? I had a hell of a time finding a rebuild kit for it, even after getting a part number from Holley for the kit that was supposed to work for that carb. It didn't work exactly...gaskets for the metering plate and bowls were wrong and I had to buy and modify separate gaskets. Also, it's a pain to mount that carburetor to an intake manifold because the rear studs have to be cut to exact length and then you can just barely get the nuts started because the carburetor is so wide at the back to accommodate the large rear secondaries. I ended up changing to an Edelbrock EPS (square bore) intake manifold and an Edelbrock carburetor that I had. Yeah, I know you said you didn't want to change the intake manifold, but in my case the performance difference was night and day with the spreadbore Holley being the loser. I would've used a Holley 4150 or 4160 instead of the Edelbrock carb if I'd had one laying around.
Would this be a solution ? https://www.ebay.com/itm/Holley-621...4fcb89da2001223917f4|ampid:PL_CLK|clp:2334524
Using the manifold in your picture and a Holley R-1850 carb (600 CFM 4160). The carburetor has 300 CFM on the primary, and 300 CFM on the secondary. The manifold with a square->spread adapter permits about 150 on the primary. Added to the 300 on the secondary..................presto! you now have a 450 CFM carburetor! A 600 CFM 4150 would have the same airflow. Jon.
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