IF vs EF 962 crankshaft & rods

[Bill W.]

Are the rods and crankshaft made out of the same material on a IF 396 and a EF 396 . Both are 962 blocks and both are 4 bolt main and were cast in 65 .

[Joe L.]

Re: IF vs EF 962 crankshaft & rods

Are the rods and crankshaft made out of the same material on a IF 396 and a EF 396 . Both are 962 blocks and both are 4 bolt main and were cast in 65 .

Bill------


The material is the same. However, the rods and crankshaft in the IF-coded engine are not the same as those used in the EF-coded engine.

[Bill W.]

Re: IF vs EF 962 crankshaft & rods

Thanks Joe . I had read that the IF had forged rods and the EF were cast . And my IF crank is forged and cross drilled I have not removed the crank or rods from my EF block yet . Are there any other differences ? My IF crank has a spun main bearing ,it will need turned . What is the difference in the rods ??

[Wayne M.]

Re: IF vs EF 962 crankshaft & rods

Bill------


The material is the same. However, the rods and crankshaft in the IF-coded engine are not the same as those used in the EF-coded engine.

Believe there were no IF's made after the '65 MY ended for Corvette. The EF shows in Colvin as 396/360 4-sp for the '66 MY, although it could have been cast/assembled in calendar 1965. (Again) Colvin shows the crank casting 3856223 used 1965-69 in 1965-1966 all, and '67-69 Hi-Perf passenger.

Pic is of my "961" block crank, cast May 14th '65, which, other than not being X-drilled nor tuffrided (surface treatment), is the same 6223 cast crank as the "IF" Corvette block.

[Keith B.]

Re: IF vs EF 962 crankshaft & rods

Just curious whats the vin stamp on the EF block along with the cast date. Always looking for my original block for my car

[Bill W.]

Re: IF vs EF 962 crankshaft & rods

Hi Keith . I have two 962 Chevelle 4 bolt blocks I cant get to them good enough to read the dates but they are both for 66 chevelles . The best I can read them they are TI030EF ....F104673 1966 360 horse short block The second one is T1007EJ ....6Z108326....1966 360 horse .bare block.
I forgot I had another Chevelle 396 . It was in my 65 when I bought it . I gave it to my brother about a year ago . I dont remember what the code was but I think it was a 66 or 67 small horse automatic ????? It was not a 962 block .I can look at it next time Im over there .

[Joe L.]

Re: IF vs EF 962 crankshaft & rods

Thanks Joe . I had read that the IF had forged rods and the EF were cast . And my IF crank is forged and cross drilled I have not removed the crank or rods from my EF block yet . Are there any other differences ? My IF crank has a spun main bearing ,it will need turned . What is the difference in the rods ??

Bill------


No Chevrolet V-8 EVER used cast connecting rods. All were forged steel. However, there were other differences. Just what the differences were between the rods used in the IF-coded engines and the EF-coded engines, I do not know.

I believe the differences in the SHP cranks and the HP cranks involved Tufftriding and/or cross-drilling.

[Wayne M.]

Re: IF vs EF 962 crankshaft & rods

...... I believe the differences in the SHP cranks and the HP cranks involved Tufftriding and/or cross-drilling.

This is the 6223 cast crank from my 2-bolt '65 "961" block. When I first saw this, I thought it was X-drilled, but apparently not. Supposed to be even MORE oil passages.

961crank (not) X-drilled.jpg

[Keith B.]

Re: IF vs EF 962 crankshaft & rods

Hi Keith . I have two 962 Chevelle 4 bolt blocks I cant get to them good enough to read the dates but they are both for 66 chevelles . The best I can read them they are TI030EF ....F104673 1966 360 horse short block The second one is T1007EJ ....6Z108326....1966 360 horse .bare block.
I forgot I had another Chevelle 396 . It was in my 65 when I bought it . I gave it to my brother about a year ago . I dont remember what the code was but I think it was a 66 or 67 small horse automatic ????? It was not a 962 block .I can look at it next time Im over there .

nope not my car. but interesting you have one block from the Freemont CA plant and anther from the Flint MI plant.

[Bill W.]

Re: IF vs EF 962 crankshaft & rods

Keith the EF was a complete engine out of a wreck . The EJ was an old drag racing block . both came from the St Louis area in the early 1980s . I bought them before I knew they should have ribs .

[Wayne M.]

Re: IF vs EF 962 crankshaft & rods

Keith the EF was a complete engine out of a wreck . The EJ was an old drag racing block . both came from the St Louis area in the early 1980s . I bought them before I knew they should have ribs .

Bill --- I believe the last 962 (& 961) blocks that had front and rear ribs had casting months in the H/I/J period of 1965.

[Patrick B.]

Re: IF vs EF 962 crankshaft & rods

From the build dates of Bill's 66 962 blocks, they are probably "I month" (September) castings without ribs. This would suggest that August 65 962 castings were the last to have ribs and thick cylinder walls.

[Bill W.]

Re: IF vs EF 962 crankshaft & rods

Patrick I never understood why they would change the castings by eliminating the ribs and changing the cylinder walls without changing the casting number ?????
I also always thought the 65 425 engine was a practice run for the L88 . The 65 engine had allot of heavy duty parts the 66 425 didnt have and the 67 L88 did . Or is that just wish full thinking on my part ?

[Joe L.]

Re: IF vs EF 962 crankshaft & rods

Patrick I never understood why they would change the castings by eliminating the ribs and changing the cylinder walls without changing the casting number ?????
I also always thought the 65 425 engine was a practice run for the L88 . The 65 engine had allot of heavy duty parts the 66 425 didnt have and the 67 L88 did . Or is that just wish full thinking on my part ?

Bill------

It is very unusual for cylinder wall thickness and reinforcing ribs to be changed without a change in casting number. However, that's what apparently occurred here. I've seen situations in which FAR more minor changes to a casting were made and the casting number did change.

As far as the 1965 L-78 using much more HD parts than the 1966 L-72, that's wishful thinking. Except for bore size (and, of course, pistons), the componentry of the 1965 L-78 was virtually identical to the 1966 L-72.

[Bill W.]

Re: IF vs EF 962 crankshaft & rods

Joe . The L78 & L88 both used the same starter , flywheel , radiator ,core support . They both had ribbed blocks . The 66 didnt use any of these .I am not sure if a 66 425 used a cross drilled crank or not .