vickycar

have a 400 engine with 425 heads, everything I've read says they are interchangeable, but my question is do you use 425 push rods and lifters or 400 push/lifters. parts books list them as different lengths.

joe_padavano

What year 425? What year 400?

Both are BBOs and the head castings interchange. The differences in pushrod length are likely due to the differences in lifter bank angle. In 66-67, Olds machined the blocks for both 39 deg and 45 deg lifter bank angles, depending on application. The different lifter bank angle changes the required pushrod length. Bottom line is that the BLOCK primarily determines the pushrod length, however due to the non-adjustability of the Olds valvetrain, minor differences from stock (due to valve machining, head milling, etc) can sometimes require a non-stock pushrod length. If the motor has ANY differences from original, it's good practice to check the pushrod length. Also, while the head castings were the same, the pushrod holes are drilled slightly differently for the 39 vs 45 deg lifter bank angle. You should also check pushrod clearance in the hole in the head and open the pushrod hole up if necessary.

vickycar

67-400 390925e block heads are c heads off toro 67?

vickycar

thanks joe ,that would explain why the pushrods we took out were slightly bent. should I be using the 400 lifters or 425 lifters.

Oldsmaniac

The E block 400 has the same size lifters as the 67 Toro 425. If you had bent pushrods it was most likely from stuck valves rather than too long of a pushrod. The E block and Toro 425 also have the same lifter bank angle. Both used C heads from the factory with the large intake valves.

joe_padavano

^^^THIS. Both the E-block 400 and the D-block 425 used in the Toronados came with the same 39 deg lifter bank angle and the hard-to-find 0.921" lifters. Pushrods should be the same for these two motors. D-block 425 from non-Toro applications (namely, Delta 88s and Ninety Eights) used the 45 deg lifter bank angle and 0.842" lifters. Those pushrods are different.

Kennybill

The original 425 engine out of my 1967 98 is a D block, C heads, 39 degree cam angle 0.8420 lifters block. I have one other 1967 425/D block/C headed engine that also is 39 degree small lifters. 1967 425s can be 45 or 39 degrees with the smaller lifters. JMO

Oldsmaniac

My 67 non Toro 425 also is a 39 degree, 1967 was a year where you must check your 425 to be sure of lifter bank angle if its not a large lifter block.