Swapping 330, 400, 425

320400425

New member
Dec 19, 2019
21
1
1
Buchanan Georgia
Hello
i decided to join to get some help and knowledge from real olds fans.

i have three olds motors. The current completely reconditioned motor is a 330 which sit in my 1066 442 which is 90% body off to date. I have finally found the right engine after 9 years of looking.

i was afraid I would never get the real engine so I decided to go with the best 330 I could get. It has heads and cam that equal what was on the 442. I had them special built at a speed shop.

my question is that in two days I will receive my complete 400 - yes complete. I will also be receiving a complete 425 - yes complete. The guy is also throwing in dual exhaust systems and flex plates and the lot.

he is delevering them from 360 miles away and going to unload them onto my engine stands - all for $1,350. Please tell me if this is the deal I think it is.
 

Olds 307 and 403

Active member
Oct 4, 2018
463
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Melville, Saskatchewan
Many parts will interchange especially between the 400 and 425, both are big block(BB) or a taller deck than the 330 small block(SB). The SB is 260 through 403 and the BB is 400 through 455. That means the 330 uses a different intake manifold, pushrod length also has smaller ports in the heads. Another thing to remember is the 400 should have a 39 degree cam angle and the 425 may have either the same 39 degree but also could've had a 45 degree cam. The cams can not be swapped if they have different angles. All 3 have steel cranks, 330 is a 3.385 stroke with 2.1" rod journals and 2.5" main journals. The 400 and 425 have the same 4" stroke crank with 2.5" rod journals and 3" main journals but would be balanced different, different bore sizes, 4" for the 400, 4.125" for the 425. This is assuming a 65 to 67 400 motor and not the 68-69 less desirable 68-69 tiny bore and long stroke 400, 3.875" bore and a 4.25" stroke, hugely undersquare. That later 400 motor would only be valuable to a matching numbers 442. Dual exhaust is a good idea on any of the motors, they all have the same exhaust attachment points. But the 400 and 425 may have the better performance, larger cast iron exhaust manifolds. The 330 will have log manifolds, extra outlet can be capped, cap still available new. The high performance BB exhaust manifolds won't fit the 330 due to deck height. Thornton makes reproduction high performance BB manifolds, better SB manifolds called the JR, and shorty headers for both. This is reason for SB and BB headers. The SB headers won't fit the taller deck BB and BB headers will hang low to the ground on a SB motor. Good luck and yes it is a good deal if the motors were properly stored and turn over by hand..
 
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320400425

New member
Dec 19, 2019
21
1
1
Buchanan Georgia
The engine code on the 400 is 390925E.

When I had my heads for the 330 built and matched to push rods, lifters, cam etc they said they would make sure they were 39o bank angle.

is this possible? I have yet to put them on the motor. They are all aluminum heads. The good news is that all motors have original heads.

the 400, from the photos, looks like the heads have been done recently - as far as I could tell.

how would I go about making sure a cam is at a certain angle of not. I want to make sure it is 39o before I stick one in there. What about intake manifold? Distributer and oil pump?

ipurchased new high pro oil pump from mondell

both engine do turn over and the guy selling is driving almost 400 miles with any deposit down on my part. So I trust he is very confident. He also builds Chevy cars.

thank you for great information on my thread. I did not expect to get so much from one reply.
 

Olds 307 and 403

Active member
Oct 4, 2018
463
165
43
Melville, Saskatchewan
Distributor is the same, intake is wider on the BB. Except for 67, the 330 should be 45 degree. You measure in the valley to make sure of the cam angle, I believe all early 400 were 39 degree cams with big .921" lifters. Oil pumps work for all Olds V8's, regular volume is fine for most builds.
 

320400425

New member
Dec 19, 2019
21
1
1
Buchanan Georgia
I am very excited about my new 400.

Two years back I had a speed shop put together a high performance top end kit for my 330. I had this done because I feared I may never find the correct 400. After all, I have been looking for the correct 400 for 8 years or more.

Will the new aluminum heads that I purchased for the 330 motor fit the 400? Good or bad idea? Why?

The package I purchased included high performance heads, all the springs and valves are there. I also had a 45o bank angle cam, new lifter and heavy duty lifters.

I know the cam, lifters and push rods won’t work but the roller rockers will.

Any input is greatly appreciated.
 

Olds 307 and 403

Active member
Oct 4, 2018
463
165
43
Melville, Saskatchewan
I would assume they are Procomp or Edelbrock heads. Take a picture, they should definitely work as those are designed for the BBO and just fit the SBO.
 

320400425

New member
Dec 19, 2019
21
1
1
Buchanan Georgia
Here is ID info. They are ProComp.
can you tell me if this is the correct piston for a stock 400 or are they aftermarket?

what would be the be if it’s of the ProComp over the stock B heads. The valves seem to be the same size.
93CDAF1A-0F3A-4500-9C06-E5D4643033A7.jpeg

7E4D091A-52AD-452C-84B7-836884E4F75E.jpeg
82F70988-8DF5-4A8C-AC00-33F4A727B84F.jpeg
 

Olds 307 and 403

Active member
Oct 4, 2018
463
165
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Melville, Saskatchewan
Is that valve contact on the pistons? Those are definitely high compression pistons. Measure the Procomp chambers, they should be around 83 to 84cc untouched, similar to nearly any stock BBO heads.
 

320400425

New member
Dec 19, 2019
21
1
1
Buchanan Georgia
Is that valve contact on the pistons? Those are definitely high compression pistons. Measure the Procomp chambers, they should be around 83 to 84cc untouched, similar to nearly any stock BBO heads.
All the pistons have that same half circle I dentions that look like the valves have touched the piston. But would the valve move that distance and stay in the same line.
 

Olds 307 and 403

Active member
Oct 4, 2018
463
165
43
Melville, Saskatchewan
It could be clearanced pistons. I used plexiglas with a hole drilled, vasoline to seal and a CC syringe adding dyed washer fluid. Spark plugs must be in see how many CC the chambers are. The Procomp 2.07"/1.625" probably just cleared the 330's bore.