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-   -   350 block into 327 (http://www.hotrodders.com/forum/350-block-into-327-a-228889.html)

ryder57 01-27-2013 06:06 PM

350 block into 327
 
A friend of mine was cleaning out his shop and gave me lots of parts. I ended up with a 1968 chevy 307 complete with 305 heads on it and a bare 350 4 bolt main block. Since i have a good 350 block what do i need to make it a 327. He also gave me a edelbock dual plane intake, Holley carb, and HEI distrubtor. I dont want to sink alot of money in this freebie so i would like to use the 305 heads. When I'm done it will end up in my 55 truck thats a daily driver not a racer.

BOBCRMAN@aol.com 01-27-2013 06:09 PM

307 crank, 327 pistons ,350 block= 327

ryder57 01-27-2013 06:11 PM

Sorry forgot to ad the block is 95-00 cast#10243880 and i have the roller lifters can i re use them?

Plaintoast 01-27-2013 06:43 PM

if you're looking to use what you have and spend as little as possible, as was already mentioned, 350 block 307 crank. get an adapter to run the two piece seal crank in the one piece block.
if the lifters seem to roll and collapse ok, i would say go ahead and try it.
using 305 heads is going to drive up the compression, and i don't think I've ever seen a dished 327 piston. that may be what stops the project from being cheap.

prumora1 01-27-2013 07:27 PM

reply
 
first your putting 307 pistons in a 350 block. 307 pistons are to small in diameter,

however 307 are good little runners capable of descent hp and high rpms.
my suggestion re-ring and re-bearing the 307 and do the 305 heads for good flow, 190 intake runners with 2.02/1.60 valves and dual plane intake will make a good street engine...

ryder57 01-27-2013 07:47 PM

I have the pistons and rods for the 350. Can I use these pistons and which rods do I need. If the 305 heads bump up the compression what about some vortec heads will they be ok? I'm sorry guys I don't know much about this and I appreciate all the help.:confused:

BOBCRMAN@aol.com 01-27-2013 08:25 PM

350 piston has wrong pin height. 327 is only piston that will work.

Stock rod is same length for all three engines.

67-4-fun 01-27-2013 11:56 PM

i believe you will need a piston with a compression height of 1.675 using a 5.7 rod... with your 307 crankshaft {3.25 stroke} inside a 350 block.. bingo there you have a large journal 327

techinspector1 01-28-2013 12:25 AM

,
Quote:

Originally Posted by ryder57 (Post 1639528)
I have the pistons and rods for the 350. Can I use these pistons and which rods do I need. If the 305 heads bump up the compression what about some vortec heads will they be ok? I'm sorry guys I don't know much about this and I appreciate all the help.:confused:

Each and every one of us began knowing absolutely nothing about an internal combustion motor, so don't feel bad.

Let me try to help you out with some basics.....
If you're looking at a bare block from the front or rear, you can see the centerline of the main bearing bores where the crankshaft bolts into the block.
From that centerline up to the block deck where the heads bolt on is called the block deck height. On a virgin block that has never been decked or had the main bearing bore altered, that block deck height on a small block Chevy measures ~9.025". When we're choosing parts to fit into the block, we add half the stroke (the radius of the stroke), the connecting rod length (center to center) and the compression height of the piston (distance from the centerline of the wrist pin to the crown of the piston just above the top ring) to find what we call the "stack" of parts to be used in the build.

Now, we know that the stroke of a 327 crankshaft is 3.250". If we divide that figure by 2, we come up with a crankshaft radius of 1.625". If we use a Chevy 5.7" rod and a 1.675" compression height 327 piston along with a 1.625" crank radius and add these 3 values together, we will get a "stack" height of 9.000". Now, if the block deck height is 9.025" and the stack is 9.000", then we know the stack we're planning to use will work and will leave the piston 0.025" down in the bore with the piston at top dead center.

It's the same routine for any motor, just different measurements. For instance, a 350 block would be 9.025" block deck height. The stack for a 350 would be 1.740" crank radius, 5.7 rod length and 1.560" piston compression height. Adding up the 3 stack components, we find a stack height of 9.000", leaving the piston down in the bore by 0.025" with the piston at top dead center. The 0.025" figure is called piston deck height, not to be confused with block deck height.

Same 350, but with a "rebuilder" piston that uses a compression height of 1.540" instead of 1.560" The pistons are made shorter on the compression height to allow the shop to cut the block decks by 0.020" to freshen up the decks if they are a little warped or if you want to equalize all four corners of the block deck with the centerline of the main bearing bore. This would leave us with a block deck height of 9.005" and a stack of 8.980", keeping the 0.025" piston deck height (piston down in the hole by 0.025" with the piston at top dead center.)

cobalt327 01-28-2013 02:42 AM

Quote:

Originally Posted by ryder57 (Post 1639458)
Sorry forgot to ad the block is 95-00 cast#10243880 and i have the roller lifters can i re use them?

This is a 1-piece rear main seal block. Factory 327 cranks are 2-piece rear main seal blocks. You'll need a 1-piece to 2-piece RMS conversion setup to use a 327 crank.

Why not use a 350 1-piece RMS crank if this is a budget build? Besides, there is not one good reason to toss away the displacement just to say "I got a 327!"- especially in a truck.

454C10 01-28-2013 04:32 AM

Get the right 350 crank.

Reuse the rollers. But a new roller cam will cost you.

cdminter59 01-28-2013 05:59 AM

350 block into 327
 
Quote:

Originally Posted by prumora1 (Post 1639516)
first your putting 307 pistons in a 350 block. 307 pistons are to small in diameter,

however 307 are good little runners capable of descent hp and high rpms.
my suggestion re-ring and re-bearing the 307 and do the 305 heads for good flow, 190 intake runners with 2.02/1.60 valves and dual plane intake will make a good street engine...

Man, get you some glasses so you can see. BOBCRMAN said 307 crank, 327 pistons ,350 block= 327 cid.

cobalt327 01-28-2013 06:36 AM

Clarification
 
Quote:

Originally Posted by cobalt327 (Post 1639623)
This is a 1-piece rear main seal block. Factory 327 cranks are 2-piece rear main seal blocks. You'll need a 1-piece to 2-piece RMS conversion setup to use a 327 crank.

Why not use a 350 1-piece RMS crank...

This is if you want to keep the 307 together, obviously. The problem w/using a 307 crank for a 327 is the balance will be off, and there's a chance the crank will need Mallory added. That gets expensive real quick. Of course, you could build it and not balance it, but I wouldn't recommend it. You can get away w/using a stock 350 crank and the balance will not be perfect, but will be closer than a 307 crank.

F-BIRD'88 01-28-2013 10:15 AM

sell the 350 block to fund some hot rod parts for the complete 307. It will make a very good motor for your truck.
Depending on which 305 heads you got (casting number) they can be turned into a fairly decent street perf head with generous hand porting. (don't be shy, lean on that die grinder) And that combined with the small chamber will wake up the 307.
when you get the heads all tuned up, reinstall on the 307 with a thin felpro 1094 head gasket.

The best of the 305 heads to start with are the 4416 castings. Best when generously home/hand ported with 1.94" valves added.
Mild, moderate hyd cam, hi rise dual plane 600-750carb headers. You will be suprised how good it runs.
when you hot rod a 307 with improved compression ratio 9.8-10:1 and added improved port air flow it makes a lot lot more power than stock.
Much like a 327. A lot less fuss.
Spend the money where it will do the most good.

prumora1 01-28-2013 02:43 PM

ryder57? everyone one here had to start somewhere, we weren't born with it. however some of us got a early start at it. my philosophy is the K.I.S.S method.

K keep
I it
S simple
S stupid

im not calling you stupid, its just a phrase. remember this just because all Chevrolet small block engines are built around the same platform there is a lot of differences inside, in not as simple as everyone makes it out to be. so start simple and work your way up.


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