401 or 425 ????

[rg]

I have a 63 RIVERIA, HOW CAN I TELL IF ITS A 401 OR 425??? THANKS RG

[larkone]

it will say 445 on your air cleaner if it's a 401 if it's a 425 it will say 465, and i think the 401 was painted silver and the 425 green.

[wildcat1562]

look for the casting numbers
here ya go
Greg :beer
Block Cast # Year Displacement
1169334 56-59 322
1173201 59-61 364
1174372 59-61 364
1185484 59-60 401
1185404 61-66 401
1196546 61 401
1196547 61 364
1340146 63-66 425
1346046 61-66 401
1349046 62-66 401
1354713 64-66 425
1354714 64-66 425
1364704 63-66 425
1364705 64-66 401/425
1364707 63 425
1364714 64-66 401

[rg]

THANK YOU VERY MUCH. :beer

[flynbuick]

Got a lead on a local 425. I know little about nailheads. I assume the casting numbers are on the front on the block? What is the range of price to pay for a core 425?

[flynbuick]

Ttt

[Brian]

Look at the top front of the block--right behind the thermostat housing on the surface where the valley pan gasket meets the top of the block. There will be numbers stamped there. On the left is the 2 letter engine id number, and on the right is the VIN number for the vehicle it was in.
If it is a 425, the second letter in the id will be W or X (w is single 4bbl, X is 2-4bbls.) The first letter is the year (J=63, K=64, L=65, M=66). If it is a 401, it will have an R or a T for the second letter (T=most all 401s, R=specific code for the 401 in the '65 and '66 Skylark GS).
Check out this website for all the details and a complete list of everything:
http://www.buicks.net/shop/reference/engine_ident_63_75.html

[Poppaluv]

it will say 445 on your air cleaner if it's a 401 if it's a 425 it will say 465, and i think the 401 was painted silver and the 425 green.

In '66 The Nailhead went red.

Brian the X codes were factory until late March, BUT you could still get them (duals) as a dealer installed optioned after, along with the aluminum finned valve covers.

Yours is prob. a 401 unless it's a transplant, they weren't offered in '63 :3gears:

[Brian]

Actually the 425 was offered late in '63. I have seen with my own eyes a '63 Wildcat 4-speed car with a factory installed 425 in it. The original owner still had it when I saw it (he had it for sale when I saw it). He ordered it late in the model year and they had the 425 available. Very rare in a '63 though. It was a single 4bbl. engine.
And yes, my '65 GS came with an LR code 401 in it.

[riv2x4]

Actually in 66 only 425 went red. The 401 was still Buick green.

Larry
In '66 The Nailhead went red.

Brian the X codes were factory until late March, BUT you could still get them (duals) as a dealer installed optioned after, along with the aluminum finned valve covers.

Yours is prob. a 401 unless it's a transplant, they weren't offered in '63 :3gears:

[Brian]

Except in the '66 Skylark GS--the 401 was red in it. 401 was green in everything else.

[Poppaluv]

Corrected.... :TU: So were ALL 425's in any year, painted red???

[riv2x4]

1966 425's were painted Red. That is the only time 425's were Red.

Larry

[Brian]

Red didn't come along until '66. All 340's were red--both 2bbl. and 4 bbl. versions. All 425s were red, and the 401 only in the '65 Skylark GS was red.
The 225 V6, 300 2bbl. (no 4bbl. 300 available in '66), and the 401 in anything but the skylark GS was painted green.
Another interesting note--all 425s that came in '66 Riverias had a spreadbore intake and a rochester Quadrajet carb on them.