what are you guys running on your y blocks? My '56 came with Holleys 1850S, but it hasnt seen gas in 20 years, so im thinking about just getting the same one to replace it with, but maybe the 80457S with an electric choke maybe? Thier both from the 4160 street performance series. what are some other good and affordable options? (side note - im not an engine guy, i barely get by doing tune ups and basic stuff lol)
http://www.summitracing.com/parts/hly-0-80457s/overview/ http://www.summitracing.com/parts/hly-0-1850s/overview/
This has gotten very positive reviews on several forums:http://www.summitracing.com/parts/sum-m08600vs In a fair amount of cases an improvement of 2-3 more MPG,Summit got it right with this! with some design features from the 4100 Autolite and the ability to tune it with readily available Holley parts, notice a great sale price on it now and it also comes with the CD-ROM tuning video a big help for novice tuners
I put a Summit 600 CFM carb on my 56 with a 302. The first one whistled just off idle and had a leak around the ****erfly shaft. It was replaced with no problems. The second one also whistled. I was either on or off the gas to keep it quiet. I'm talking a really irritating whistle. Summit said they must have gotten a bad batch of carbs and sold me a Holly for about $70 more. All of this was handled over the phone with no h***le. The Summit carb ran nice and was easy to tune, I just couldn't stand the whistle.
If the 312 is stock and will not be raced, a 500 CFM Edelbrock with give good performance, good fuel mileage, and great low RPM throttle response. A 600 will give a bit more top end, and use more fuel. They both can be ordered with electric choke. On any Edelbrock, use a spacer to keep it cool.
I like the 1848 Holley. 465 cfm. Gives a little better throttle response than the 1850 and is readily available. you are already halfway there if you are using the B manifold which flows better than the A manifold with an adaptor and hopefully, though you dont mention it, you are using the later mechanical/vacuum distributor. With this combination and a twin exhaust (doing away with the crossover pipe) your engine should sing along nicely.
Today 07:50 PMBeamy hopefully they took care of the whistle lol,...how long ago was this? A month ago. They said it might be that when they stamp the ****erflies they have too sharp an edge and to try filing them. I did but it didn't help. The Holley doesn't whistle. It sounded like a really bad vacuum lead, real shrill. I'm not crazy about their carbs but like their customer service.
Here is another option:http://www.ebay.com/itm/Edelbrock-Carburetor-500-cfm-/281136432926?pt=Motors_Car_Truck_Parts_Accessories&hash=item417509871e&vxp=mtr I had never read the issue about the Summit Carb whistle problem so I Googled it and every thing I found pointed to Holleys with vacuum leak issues.
I second the use of the 500 cfm Edlebrock. I am running it on a 302 (307 now) with very good results. I chose the manual choke version because my 54 has one on the dash. It starts good, idles good and throttle response is good. Not a race car but sure drives nice.