Hey everyone, I tried searching and found some info on the topic. For example my understanding is that the C355 will not work on anything but the 265, because the intake ports are more narrow than a 327, for example. What I don't know is if the C357 is OK for my 55 265, or if I should hold out for a C355. To me if the C355 is too narrow for a later SBC, and the C357 works with either, the intake runners on the C357 are (significantly?) wider than the ports on the 265. Anyone have some advice? Thanks, Aaron
I have never seen a c355 manifold? I am running a 265 tri power on vortec heads. use a intake gasket to ensure you have a good seal and either match port one or don't worry about it?
The 1955, 265 intake manifolds, were a one year only design; the temperature sending unit location is at the left rear, and there is a "bung" for the optional oil filter, oil return line, just to the right of the carburetor. The oil plash shield under the manifold is small also, compared to the 283 and later engines.. All 55 and 56 265's used a different intake manifold gasket because of the extremely small intake ports; the exception is the "late" 56 dual quad equipped engines. Those engines used larger ports. IF your engine is in a 55 Chevrolet, keep those things in mind. You may be able to get a later style intake to "seal" by using the "right", 265 intake gaskets, but there will be differences in how the ports meet; you should be able to port match the heads to the intake, or the intake to the heads. It's doubtful you'll see any performance increase due to the small port/valve heads of the 265. Butch/56sedandelivery. As far as the Edelbrock intakes go, the difference between the C355 and C357 is going to be in the port size, where the temperature sending unit location is and will be tapped, and the oil return line "bung". If you have a C355 use it, if not, look for one, or do the modifications to make the C357 work.
Thanks for the info! I don't have a C355 but will keep my eyes open at the Portland swap meet this year. Aaron
I just bought a C355 for my 283, but now reading this it looks like it may not work? Is the C355 really a one year only intake for 265's?
The C355 manifold will work just fine, as long a 265 specific gaskets are used; in fact, 283 gaskets may work also, because the ports are still fairly small. Now, if you were to try it on a 327/350, you'd have to definitely use the 265 specific gaskets. There will be some marginal decreases in performance, due to the smaller port sizes, but most guys only use them for "appearances" anyway. The one year deal only has to due with the location of the water temperature bung location, and the boss for an oil return line to the engines valley area. Just plug the oil return boss, use 265 gaskets, and use a temperature gauge that will work with the bung location. Or, send me the intake, and I'll give you a dual quad setup; Weiand manifold and matching, rebuilt, TRUE Carter AFB carburetors. I am Butch/56sedandelivery.
splain to me the numbers you are tossing around. I have a 2 bbl 55 265 and am looking for a 4bbl intake.
A "STOCK" 1955, 4 barrel intake manifold is # 3711348; they are getting harder to find since the NHRA has allowed the Tri-Five Chevrolet's back into Stock Class. 55-56 heads have SMALL ports/runners, so the C355 tri power intake, and the ones made by Offenhauser and Weiand, have small ports also. The 55 intake manifolds were unique, as that was the only year the water temperature, sending unit bung, was placed at the left rear of the manifold (from the drivers position looking forward). Those intakes also had an oil return port on the right side of the manifold, that oil coming out of the remote oil filter, was returned to the engine. 55 and 56 ports are basically the same, however, the late year, 56, dual quad intakes had slightly larger ports. Good luck finding a pair of those heads, or affording them; they bring $$$. 1957 Chevrolet V-8 heads, 265 and 283 engines, had slightly larger ports than the 55-56 heads. The C557 tri power intake has larger ports for that reason, but they still don't have the bigger ports of the performance 327's and the 350. You can swap heads and intakes around all you want. The issue is getting them to seal, without vacuum or water leaks. There are plenty of C355 tri power intakes sitting on top of 350 engines; the tri power's are more for show mostly, so a little decrease in performance won't hurt. 265's also had small combustion chambers, right around 55.6 CC 's, while 283's were around 60 CC's, 327's around 64 CC's, and some of the post 70 350's had 76 CC chambers. You could use a 56, 265 4 barrel intake on your 55 heads, and use a longer water temp thimble and line; you'd have to drill an oil return IF your 55, 265 has the optional, remote, oil filter (usually bolted to the thermostat housing). you may get buy with some aftermarket intakes also, but you'd have to use 265 gaskets, and make sure there are no leaks (water or vacuum). Course when you see an advertisement, for say an Edelbrock intake manifold, and it says it will fit 55-87 V-8's,. they're hoping you know the tricks to make it work, IF it works. My head's starting to hurt! Look in the classifieds here at the tri power SBC intakes, and compare port sizes, and water temp bung locations. I only say tri power here, because that is what the OP wanted to know. I am Butch/56sedandelivery.
Thanks Butch. I have an original 55 265 with a 2 bbl. I was hoping to up grade to 4 bbl. Not interested in the tri power.. Really only interested in the edelbrock c3b. May just the 2bbl .It does have the oil filter. Going into a model a frame.
ALL the Edelbrock C3B/C4B, etc, have the larger port size (327 head ports). You may have issues getting one to seal to the 265 heads. Keep your eyes open for a "boat", 283 intake. They are exactly like an early, stock, cast iron, 283 4 barrel intake, only made of aluminum. I have one, and there's been one on E-Bay for a while now (they're asking too much, something like $399 item number 171260280261). E-Bay item number 371916508457 is a stock, cast iron, 4 barrel, 1955 intake and early 55 4 barrel carb (see the small ports?/55 used an early and late 55 carb-the linkage was different between the two). See where the temperature sending unit bung is, a one year only intake There are also several 56-57 265 and 283 intakes as well on E-Bay. Just drill/tap a hole for an oil return line. I am Butch/56sedandelivery.
Do not mean to hijack OP thread, but have the Offy version #3287, of the 265 3x2 manifold. I am putting it on a '66 truck 283 with power pack heads. The port opening on the manifold are slightly smaller than the head ports, but still line up. My question is what is the difference between the 265 and 283 intake gaskets?
Ports are smaller, therefore the gaskets are smaller. Use the 265 gaskets with your swap; Fel Pro MS9200B. The C3B intakes were actually meant to be used with the Holley three barrel carburetor. A C4B manifold may be an early early one with a 4 hole carb mount (good if you can find one as it may have smaller ports), or a split, 180 degree type carb mount. You can use a C3B but there's a notch in the secondary portion of the divider; that may actually help to "balance" out the overall flow. Chevrolet sent out a service memo to dealerships, where mechanics were instructed to create a "notch/trough" between the primary bores. I am Butch/56sedandelivery.
True Vortec heads have a different mounting than 1rst Gen SBC heads, and can't take an earlier intake manifold unless re-drilled. Maybe you actually centerbolt heads, also referred to as swirlport, that are similar to Vortecs, used on both the 305 and 350 engines after 1987. Swirlport heads still have the earlier intake manifold mounting, but the center 2 mounting holes on each side are at a different "angles"; there are wedges made to allow their use with older intakes;, but some guys just "slot" those center holes for the bolts to align with the heads. Some aftermarket Vortecs have both mounting patterns for the intake manifold. True Vortec heads have the "heart shaped" combustion chambers. I am Butch/56sedandelivery.
Butch, I may be up for a trade or will sell outright. Here is what I have. Thanks a ton for the info!
I see two pipe plugs in the photo, the horizontal one looks to be 1/8 NPT, and the upper one looks like 3/8 NPT.
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