The Stovebolt Site Forums The Shop Area Engine Shop 305 block same as 350?

Hey guys,
I have an old 305 that I want to use until I can afford a 350 in my 55 Chevy. I want to know if the 305 block has the same dimensions, motor mount locations and bellhousing bolt pattern as the 350? How about a 396 big block?

Thanks

Michael

Only diff between 305 & 350 is the size of the cylinder bores. Brian

Thanks, thats what I thought but wanted to confirm. How about a 396 big block? I just don't want to have to move welded engine mounts later.

The big block/small block mount question has an easy answer that could be wrong.

The mounts are the same.

But because the physical dimensions of the big block are different you may find that a location that worked for a small block won't for a big block.

Take your question over to the Hi Po forum and ask about a big block in a '55 (1st or 2nd as appropriate). Someone will know how it fits.

You use a 396 as an example. If you have the motor trial fit it...

Yes all Chevy V8's with the exception of the new mod. motoers use the same mounts and bellhousing.
If you are planning on some swaps. Four Wheeler Magazine has a special addition out on the stands now till Jan. 8 called 4X4 Garage. A lot of good info here to have in any Shop/Garage.

Get info first, but if you attempt this without certainty on location, then just lower the 396 into place and check for clearences regarding Distributer (about 3/4 of an inch farther back...I think) and exhaust manifold clearences. Other than that you should easily get everything to bolt up fine.

If you've got a 55 2nd. series, and it had a V-8 originally, either the 305 or the 350 should bolt in on the original mounts. The big block will require a little more effort, or if you want to go to a newer transmission/rear end assembly, you'll need to fabricate some mounts.
Jerry

does the later engines got the holes in the front of the block for the engine mounts?

Gen 1 (55-98) small blocks should all have the mounting holes, or at least that's what the GM Power catalog says.

Thanks all,
I wish I had the 396 to drop in now. Maybe Santa will bring me one! Until then, I am just trying to plan ahead. That little 305 sitting in my garage looks pathetic. By the way this is a 2nd series 55 with 58 NAPCO 4 wheel drive. Hence the need for more muscle to pull this tank along. Thanks for all the input!
Michael

Why a 396? 454s are much more common and probably cheaper to build. Oh, and they make more torque!

I can see choosing a 427 just for the cache associated with the number, but if I were replacing my 454 my first choice would be a 572 for the added umph. If the budget would stretch that far...

If you are still motor shopping another interesting alternative might be the 348 or 409 Chevy. You might be able to persuade someone those motors were an option on NAPCO equipped trucks.

If you want a big block,the "horse shoe" mount used on the '62 bigger trucks has the small and bigblock holes already there. Just bolt it to your block,get a '62 front mount pad;measure from the bellhousing mount pads to the front of the horse shoe bracket;you may have to drill holes tor the front pad. I don't remember if there's holes the right distance for a bigblock. Use the '55 V-8 iron side mount bellhousing and whatever flywheel goes with the engine.(in the 454's and 402's cases it has to be for a 454 or 402-make sure the diameter is the same as the 283 flywheel so you can use the old starter.)All the other small and bigblocks (including 348 and 409 "W" blocks)can even use your 283 truck flywheel and 11" clutch. That handles the mounts,exhaust is best custom-built. Without a doubt,your biggest bigblock headache will be steering box clearance. Smallblock-no problem;bigblock-might clear with the right headers,but it'll still be close. The smallblock truck starter will work as is. You might have to get creative to get your exhaust to clear the clutch linkage,but that'll depend on how the pipes are bent.
I'd stick with the smallblock if it was me.
Speed

OldSub, Speed,
Someone else suggested the 409, they said it would look "raw" in there. Maybe thats why you said I could trick some people into believing its factory. I am trying to make this truck look factory but have upgrades for comfort and safety. I actually have never heard of this engine. Are parts hard to find? And what is a "W" block? That sound great if it will work with the current 4speed and clutch. Do you know of a good website that I can read up on the 409? What cars/trucks did the 409 come in? I'm still open to the 454, I just thought it would be too large to wrangle into the frame rails. And isn't it only a 2 bolt main block? Unfortunately, in the end my budget will dictate a small block 350. But I might trip across someone selling a big block in good condition or a vehicle that has one. As far as steering I am going to try to add power steering. There is a kit that places the box on the outside of the frame in front of the axle. I just don't think it will work with my NAPCO axles. But I guess anything can be done with a little fabrication. Happy Holidays!

Okay so you're a young guy aren't you.

Chevrolet came out with their first modern V-8 in 1955. It was a 265, which grew to 283 in '57 and 327 a few years later, 350 in '68 and 400 about '70. 307 was common starting in '68 or '69 and later in the 70's there was also a 262. And of course we can't forget the 305, though we might want to.

Starting I think in '58 Chevy released their first 'big block' motor as a 348. The valve covers have a distinctive look and lead to the name 'w motor'. About '62 the 348 grew to a 409. The old Beach Boys hit 'She's so fine, my 409' is about a car with that motor. If you don't recognize that song I'll cry.

During 1965 Chevy installed both 409 and 396 motors in some cars.

The 396, 402, 427, 454, 502 and 572 are all basically the same externally. The 454 is externally balanced, I'm not sure which others might be. But basically if you can fit one of them in something, any of the others in the same place.

If you have a limited budget I'd recommend a 350. You might happen on a steal on one of the others, but if you do, you'll probably find just getting all the right pieces and accessories will be a budget killer. The 350 will be the cheapest to buy, install and run.

My quick Chevy V-8 history probably missed something and I may be off a year or two on some of the details, but the general concept is right. Now if you want to know anything about the next gen motors of the 90's and since, I'm not your guy. I don't know anything about them.

Any V8 you put in there will look a little different than the stock 235 straight six, so I wouldn't worry about stock appearance. I think the 265 V8 was an option in 57 or 58. They were a year earlier in the GMC with a 347 cubic inch Pontiac engine. You may be able to clear your axle with a 4X4 oil pan to fit your engine. I'm sticking wiht the old 235 and accepting a slower life style. (55 second series w/early Napco upfit)

good luck and bring your patience!
Pete

The 348 was a panic attempt by Chevy in 1958 to stop the bleeding in the sales department caused by the 57's getting waxed on the drag strip by the supercharged Ford 312's. The 348 engine was intended to be a high-torque medium truck engine, and was never intended for passenger car use. It had a really nasty habit of swallowing valves at high RPM, and putting a 3-2 barrel intake on the 58 Impala hotrods didn't help much in that department. Chevy racers were accustomed to the tight-winding 265's and 283's, and an engine that started floating valves at 5500 RPM just didn't cut it. Upping the displacement to 409, and then 427 to comply with the FIA 7-liter displacement limit in the early 60's didn't help much, so Chevy btrought out the straight valve cover 427 in 63, for the Daytona Firecracker 400, and later downsized it to 396 for the 1966 Caprice. The rest of the big-blocks were developed from the old 427 "Mystery engine" that made such a big splash at the 63 Daytona race, where none of the engines finished the race due to oil pump drive failure. Junior Johnson led the race for about 2/3 of it, then sheared off an oil pump driveshaft due to a too-high pressure relief setting (over 100 lbs). Within another 25 laps or so, every big block Chevy had retired with the same problem.

One engine nobody has mentioned yet is the small block 400. It has massive low-end torque in a smallblock package due to a 3 3/4" stroke, and as long as it's not over-revved, (6,000 RPM or less) and kept cool, it's pretty reliable. It should bolt in like any other small block V-8.
Jerry

Jerry..I have never seen or heard of a W series in a 427 displacement. All have been the standard big block we are still familiar with today. Are you sure about this? Could it have been used in large trucks only?

The W block 427 was not sold as a regular option. It was a race only engine, RPO code Z 11. They were mainly intended as drag race engines. The package consisted of the 427 engine, 2 door Impala SS body, aluminum front fenders, battery tray, inner fenders, grille,and the front and rear bumpers. This package was intended to compete with the "Acid dipped" and aluminum nosed Dodges and Plymouths. They are very rare.
The 427 that was used in the Nascar racers was a different block, though it did share a few components such as the crankshaft. This is the "Mystery Motor", though GM called it the Mk.2. To my knowlege, neither engine saw use in trucks, they were race engines only.

Longbox, you know your stuff! Do you remember "Old Reliable" driven by Dave Strickler? I believe it was a 63 Chevy Belair that had the full drag race options. It was billed as a "409", but I seem to remember it was discovered to be a 427 at one of the tech inspections after winning its class. Dang! I'm not supposed to remember stuff from 40-something years ago!
Jerry

I was in diapers when you guys were wrenching on these motors. And since I am 35 now, that means you guys are, well...how can I say this,..much more knowledgeable than I. Thanks for the history.

I recall the Old Reliable name from back then but sure didn't know it was a closet 427. I learned something new today so it is a good day.

Just my 2 cents worth,
The 400 was the only Smallblock to be Externally Balanced.
Hence the harmonic balancer and flywheel/flexplate was unique to those engines.
Thanks Jerry and Dave for the Memories...........
Merry Christmas Everybody +Regards

jomichael-
If you really want to keep a stock look stick with a 305 or a 350. If anybody asks just tell 'em it's a 265 (wink, wink, nudge,nudge...)
Although I am not familiar with prices in your area, I will tell you that I paid $100 for a complete and running 305 and $200 for a complete and running 350.
By complete I mean with all power accessories, brackets etc. in place.
Parts wise you can find anything you need in the P.A.W. catalog and many others. Many times 350 parts are cheaper because they are more common.
If you want more of a Hot Rod - by all means go with the Big Block! As they say there is no replacement for displacement. Again, parts are available for the 396 and the 454, with the 454 parts being cheaper many times. Around here a 454 usualy sells for about $400.
Regardless of your choice small block and big block chevys are some of the most popular engines on the planet - and they both have their virtues.
Good Luck with your project!
Guy

I have vague memories of that car and driver too. I think Strickler's name showed up a lot in Hot Rod magazine when I started reading it in the 60's.

I was trying to list the most common engines and skipped race only stuff like the Z11. Okay, actually I didn't even think of it...

My Suburban is a GMC and I've toyed with the idea of installing a Pontiac 455 and dressing it to look like the 347 installed in GMC trucks for a year or two.

My thought was that it would look like something GMC built back then, while providing all that horsepower and torque. Don't think I'll ever do it though.

If you painted the 455 the same color as the old Pontiac engine, it would probably take a real oldtimer to spot the differences. The lack of two short bypass hoses from the cylinder heads to the water pump would be a dead giveaway to some of us who used to fight with them when it was time to change, though!
Jerry

Jerry, I'm not quite old enough to remember Old Reliable (35), but I do read alot. Especially anything old Chevy/GMC, farm tractor, Chevy car, and old car/truck in general. I have even been known to read shop manuals for fun.
Actually, I came close to buying a 425hp 409 out of a '63 SS once. Found it at a car show in Chicago for $2000. I seriously considered it, but 1-already had the 235 under construction,2-I don't think that an SM318/od would have lived for too long behind it, and 3- hauling it home in the back of my buddies '94 SS didn't seem like a good idea. Would have made a really Baaad 'bolt though.

When I took over the Tennessee Technology Center auto shop at Pulaski, TN in 1985, there was a new, unfired 65 model 409 sitting in the corner of the shop, donated by GM when the school opened. We tore it down once, and there were still felt-tip marker numbers on the pistons from the factory balancing job! When I left 5 years later, it still had never been started. I think it went to scrap when the shop closed a couple of years after that. What a shame!
Jerry