So i have a bit of an odd situation, I have a 1966 C20 with a 250 I6, originally a 327 V8, in the long run I would like to put a 327 V8 back into it, but for now I want to put in a different engine. My main question is about motor mounts, are the 350 V8, and 305 V8 the same for the locations of the motor mounts? and if so, are they also the same with the 327 V8 and / or the 250 I6? it would be really nice if the 250 I6 and 327 V8 are the same, even even more so if i could mount up a 305 temporarily until i can get the 327 and clean it up nice.
From '58 ( '59?) to the LS block all SBCs used the same side mount location/bosses. If you want a V-8 and have one at your disposal you can also drop a big block (396-454) on the same motor mouths as the small block. the difference is the length in front of the motor mount.
If the sbc has the raised pad with the three bolt holes for the side mounts it will bolt right in. That is one of the things that makes the small block Chev engine so popular as you can swap them out without a h***le. the only before/after date is 57/58 as 57 and earlier didn't have side mounts.
Mr 48, Thanks for clearing that up I always get the year confused for side mounts, I can never remember if it is '58 or '59
bolt it in and don't worry about it. The truck engine mount brackets on the 230/250 six cylinder engine will also fit the V8 mounts. Those 63-66 trucks are pretty easy to swap motors in
You guys are great! So basically i now know i can drop the 305 in for now, then when i have everything i want for the 327 it'll be another simple bolt in swap. i have an SM420 and i believe 4.56 gearing, and on top of that the 250 I6 has asome issues that I need to work out.
Beware that 86 or 87 was when they went to the 1 piece rear main seal, so the flywheel is different, you need one from a 1987-up 4.3 V6, 305 or 350.
So is it's a pre '87 it will bolt up directly to the SM420? that makes it a lot simpler, I haven't invested much into this idea yet though, as I just found out i can get the 305 for dirt cheap if not free, or a 350 W/ ****** (needs a rebuild) for $300. i'd prefer to keep the ****** though as the reason I want the 327 is to bring it back to original as much as possible.
It's a bit confusing, they signify the block by 2 piece rear main seal or 1 piece rear main seal. So to those with very intimate knowledge of the difference it rings bells, changes brain files and signifies a few things will be different. One of them is the hole pattern in the end of the crankshaft. So, you need to get a flywheel for the crankshaft that you have.
My knowledge of gasoline engines is ever increasing, but i know more about diesels in general. the 1 piece is a better seal from my understanding, i never really thought about the crankshaft bolt pattern though. thats a good point! thanks! i'm pretty sure the 305 in their truck is a 2 piece (it's an '83 not '87, i thought he was parting out the 87. but it's the '83). i'll tackle that when get there though. Thank you very much!
on some sixes the mounts were staggered. The towers are the same, you would just have to move the p***enger side mount forward, the holes are already there.
The 305s with the one piece rear main take a 305 specific flex plate, it is weighted because that did away with the counter balance on the crank flange, the 350 for instance will have the wrong weight value.
the 305 and 350 and 4.3 use the same flywheel, look it up....I've been through that. http://www.rockauto.com/catalog/x,carcode,1384253,parttype,5348 http://www.rockauto.com/catalog/x,carcode,1059825,parttype,5348 http://www.rockauto.com/catalog/x,carcode,1059803,parttype,5348
So I've been pondering this and I noticed you said that a 454 would bolt up to the same mounts. Is there any good info on dropping a 454 into a 66 C20? someone made a good offer for his '83 and I told him to take the cash as it's more than parting out would get him. A 454 would be an awesome engine to build, and I would keep it in the truck if I did that. It sounded like that would be a simple bolt-in. And thanks for the links! I was surprised to find a bunch of 454's for really cheap ok craigslist, and may have to pick one up if it won't require too much fab work. Sent from my iPhone using Tapatalk
The big block swap is not quite so easy, you may need to make room for valve covers and possibly the distributor if you install it in the small block location. And you'll need to trim the upper frame rail edge for exhaust clearance. Cooling is not so easy either, the stock radiator may or may not be able to keep it cool enough. To make the mounts work on a big block, the best way I've found is to use the 68-70 396 mounts, which locates the engine forward about an inch. These mounts are either hard to find or expensive. They work differently than the normal small block mounts. You could also adapt the 1973 and newer style mounts, which is a completely different mount design. Also if you move the engine forward, you get into problems with the bellhousing mount, and either way you may have issues with the clutch linkage.
I have done better then look it up on Rock auto. I used one pulled from a 350 on a 305 and it shook a friend said that he thought that they were different. So I contacted Summit Racing and they sent me one after asking me the displacement and year ( also if it was a 305 HP or not) of the motor. After installing the new one (which had a different size counter balance weight [by the tape]) no more shake. Best 30 dollars I ever spent. So it appears that we have had the same problem with different solutions and good ( fair) results.
The truth is that the one I used may have just been screwed up from the start. I was just told that they were different and then when I ordered a new one they asked all those questions. So I was going on those two possibly unrelated things to start with. You are correct about the rocker cover clearance on the C-10/20 cab by the way, even tall rockers on a small block require a little clearancing on the firewall. Didn't think of it. The last big block I used in that style body/ch***is got headmons so I wouldn't know a thing about the manifolds, so thanks for the heads up on that one.
Thank you, I hadn't thought about that point yet. do you know of any good build threads? It feels like there would be more clearance in an old truck like this than in a new one. basically at the minimum I would be looking at replacing the motor mounts, possibly cutting part of the frame, and likely cutting part of the firewall to make room? whereas a 305 / 350 / 327 would literally be a drop-in swap. I'm really curious as to the 454 swap, I think this would be a great addition to the current setup, but i'll need to do alot more research. One last though I've had was the 400 SBC, but I immediately changed my mind to the 454 because of the parts availability. anyway, i'll check back in soon, and hopefully with some more knowledge of the subject.
Hantke, On a C-10/20 the engine is stuffed into the firewall. There is a little divot that the rear of the engine sits into. As for a build thread there is really nothing to it, you are putting a v-8 into a truck that came that way. On that era truck there is a difference in the bell crank for the carburetor, the 6 cylinder linkage didn't have as long a throw and on some V-8 carbs that can add up to the carb not getting pulled all the way open. But that is really no biggy, you can make the 6 cylinder bell crank work with a little fussing around. A member here called Dan is currently building a '60 with his high school shop cl***. maybe search him or contact him, he is do***enting the build.
Beware also that the 60-62 trucks are very similar looking to the 63-66 trucks, but the frame is quite different, so the stuff he does to fit an engine in his 60 may not apply to your 66. For example, they used a front motor mount instead of side mounts, and they have torsion bar front suspension.
I think that dan actually built side mounts, although he may have gone with the later Camaro mounts instead of the truck mounts.
They didn't have the big block option from what I've been told, that's where I was curious about the build threads.as I'm curious what modifications it will take. The SBC I already know will be extremely easy if I go that route. I'm actually glad it's a 60-63, im looking at a 1963 C10 short bed stepside and it looks promising, it needs some work for sure, but it's in great shape from what ive seen in it. thank you guys for the info, it's really a hard choice right now between a few different engines at this point, the 327, 305, and the 454. I'd take a 400 if I found one, but they don't seem common.
60-62 have the same frame, 63-66 have the same frame. 60-63 have the same cab, 64-66 have the same cab. 63 is an oddball.
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