Engine swap from 327SBC to 350SBC

2488 Views 9 Replies 4 Participants Last post by jlighthart, Mar 29, 2007

jlighthart

Discussion Starter · Mar 27, 2007

Question #1: Will the following parts swap from a 1967 327SBC to a 1975 350 SBC.

Original DZ 302 alum intake manifold/ long type water pump and fuel pump

327 fly wheel and starter (resurfaced about 2years ago).

Heavyduty 10.4" clutch/pressure plate (I know most 350's used a 11")

327 distributor.

Original alum 302 bell housing and M22 trans (Rear end is a rebuilt 356 positrac.

Existing 327 SBC motor mounts, power steering pump, all original DZ 302 deep pulley's and anything else.

The existing 327 SBC in my 1969 Z28 has low compression on #2 cylinder.

The replacement 350 SBC was removed from a parted out 1975 chevrolet farm pickup truck. According to the seller, it was rebuilt and bored 30 over, 5 years ago by a professional Rockingham, NC engine rebuilder. It is a 3970010 block (VO511CKW code) with GM 333882 heads (1.94-1.5 76cc). The seller pulled the pan and says it appears it has a 400 crank with 383 rods. Based on what I have read, I will have to do some head work/replacement to get the compression to about 9-9.5, so I can run a decent camshaft. The motor now appears to be assembled for torque (towing on a farm).

Question#2 Which camshaft below would work best?

Right now I have the following camshafts on hand:

Crane blueprinted # CRN-967601, 327 , 350hp, 222/222 duration, 447"/447" lift camshaft (With a set of rhoads lifters).

Wolverine Hyd camshaft #CS-274 195/202, 112/108, .390"/.410" (Seller threw this cam in with the motor. It seems rather meek by its specs.

Original GM DZ 302 2nd edition solid lifter camshaft with solid lifters. This is the camshaft I would love to install.

Recommendations will be appreciated, especially with the 1.94/1.50 heads .

Thanks;
John Lighthart

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pdq67

· #2 · Mar 27, 2007

A stock 400 uses the CS 274 cam.

And the 350hp/327 cam will be fine!.

Do some more homework and find out more about it.

If it is a 383, then it should have a scalloped 400 damper on it and either a flywheel or a flex plate w/ a "dog-knot" on it to match the damper... A short rod 383 is fine b/c my 406 has short rods in it!!!

Really check your CR too!!!!

All the drive stuff will work as a unit regardless IF you use SMALL bellhousing and starter stuff w/ SMALL and big bellhousing and starter stuf w/ BIG!!!

Small starter will have bolts across from each other and a big starter, staggered w/ the correct cast-iron snout...

As for the topend alt. mount stuff, use '69 and newer w/ the long w/p and go!!

pdq67

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TJS69

· #3 · Mar 27, 2007

Correct me if I am wrong but, don't you need a flywheel that is externally balanced with that motor ? I am assuming the one from your 327 is internally balanced and the new engine is a flexplate for an Automatic trans ? Other then that, all else should swap. Small block chevy with long water pump = small block chevy with long water pump.

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pdq67

· #4 · Mar 28, 2007

I thought I read, "400 crank"..

"The seller pulled the pan and says it appears it has a 400 crank with 383 rods."

Therefore, both the damper and the flywheel/flex plate need to be externally balanced and I'm assuming short 400 rods too, but I may be of here??

May just be 350 rods???

pdq67

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novaderrik

· #5 · Mar 28, 2007

bu what if that 400 crank got internally balanced when the engine was guilt?
if that's the case, a 400 balancer and flywheel will be a bad idea. i think i'd take the engine into a good machinist to figure out how it's balanced if you don't have the flywheel and balancer that were on it before...
and if you don't want that .390/.410 cam- shoot me a PM. i'm looking at getting that very cam for my Monte for good every day day mpg.

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pdq67

· #6 · Mar 28, 2007

Well, good question!

He can tell by looking for the slugs of Heavi-Metal that both the front and back counterweights will have in them as well as there is a good chance the crank flange looks scalloped from where access was gained to pound the heavi-metal slugs into the rear counterweight IF the Machine shop didn't h-m the flange too!!

pdq67

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jlighthart

Discussion Starter · #7 · Mar 28, 2007

I really appreciate all the input, while I try to figure out what motor I really have in hand. Hopefully this weekend I will be able to pull the oil pan and look for myself. Here are all the facts I have at this moment on this motor.

It came out of a 1975 Chevy truck (Farm use).

It was professionally overhauled 5 years ago & bored 30 over.

Block # is 3970010 / Other numbers on rt front engine tab are : 517720; 13w267486; VO511CKW.

Head #'s 333882 (F115/GM27 & M25 1/GM8 ) w/ 1.94--1.5 valves, 76cc

Still trying to contact seller to find out if it had an automatic/or manual trans (flywheel or flex plate (depending on trans)was gone. However, I noticed the threaded clutch boss above oil filter looked used, like the pivot ball was recently removed!

The engine has an 8 inch harmonic balancer.

The pistons are 4"plus a tad in diameter (cylinder walls look great--no scratches/gouges/ridges--very smooth surface areas)

Thanks to all providing input ;
John Lighthart
Chas, SC
3/27/07

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novaderrik

· #8 · Mar 28, 2007

is the balancer smooth all the way around the outside- which would mean it's internally balanced- or does it have a large chunk of it machined out around about 2/3 of the outside- which would indicate internally balanced?
odds are, if it's a farm truck, then it's just a regular 350 that's been bored over- which means all your 327 parts will work.

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jlighthart

Discussion Starter · #9 · Mar 28, 2007

I will check this out when I get off work this afternoon
Thanks;
John

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jlighthart

Discussion Starter · #10 · Mar 29, 2007

I checked out the 8" balancer on the 350 SBC *bored over 30, flat top pistons w/ 4 reliefs on each piston, block 3970010, coded (VO511CKW). It is a smooth harmonic balancer with no fat areas on the sides, or drilled out areas for balancing purposes. It's looking more like a 350, than a 400.
The heads are removed (they are #GM 333882--1.94-1.5, 76cc) and need work.

What would be a good factory replacement head to get the compression up to say 9.5; and since this is a 1970 -1975 block and I want to use my 1969 original 302 intake/holley carb, alt and pwr str pump; What year and size head should I look for? Example: Can I use 1968/1969 #340292, 64cc, 2.02int/1.60 exh/angled head w/double springs 550lb? Can I use later 1975-1979 Sbc heads?

Thanks;
JOHN Lighthart

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