What are the correct rods for a 34 21 stud

My 34 Ford

My 34 Ford

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Need some advice from the experts. I am building a 34 21 stud engine. I am missing the connecting rods for this block and need a set but what rods will fit this 34 engine and crank? Will only 1934 rods fit this block and crank or will other years fit? What is the correct length for a 1934 connecting rod? Thanks in advance for any help you can give me.
 
I believe any rods 34-38 will fit. The early ones are a little differant but the later ones will work as a set. If I rememner right all flathead rods are 7in. Walt
 
The early Ford book calls for the 18-6200 rod (which they specify at 9.25" overall length) for 1932-36 V8's. The 48-6200 rod was listed for 1937 V8's.

The 1928-48 Green Bible gives the 18-6200 rods as 32-36....to be used with the 40-6110 pistons (flat top). Then, the 48-6200 rods (at 9.125" long) as 1935-38 applications...BUT says that these are replaced by the 21A-6200 rods. Following the chart, they next list the 91A-6100 rods for 1939-41 V8's.....and these were replaced by the same 21A-6200 rods. Lastly, the 21A-6200 rods which they listed for the years 1935-42. All the above-mentioned rods have the same 2.20" big end bore.

I'm not sure if the 48-6200/91A-6200/21A-6200 rods can be used with the 1932-34 engines. There is something different about the piston pin retainers but if used in sets with piston pins, they may be interchangeable.

I do have a set of 21A rods that has the .008 oversize marking on the package. This would mean using oversize rod bearings, which are out there. I may have some of these bearings in a few undersize listings as well as standard. The big question is....can the 21A rods be used in the 1932-34 engines.
 
I believe all flathead rods are 7in. (center of pin to center of rod bore) the 32-38 had the flanged rod bearing, 39-42 had no flange but 32-42 were all 2in. journals. NOW. I don't recall if the rods were wider or the crank journal were differant length, between the 32-38 and the 39-42. I think O-Ron has that info in his head. Walt
 
Left is 33 , middle is 34 & right is 35 . The 33 rods usually aren't marked at all other than the normal L1 , L3 , R4 etc . 34 usually aren't marked either & 35 can have triangle F or an S on them . According to a June 35 parts book ALL are 18-6200 . All 3 rods in the pic are basicially the same . Note the 33 rod still has the bushing for the center snap ring in it . Wonderful stuff to deal with . I have quite a few of these from cracked blocks that were gutted for parts . Like already stated the big end bore needs to match your rod bearings .
 

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I used a set of the later flanged rods in my 33,to get the crank balanced the machinist had to put extra weight in the crank.
I only used the later rids as I didnt have a good set of the earlier ones.
Lawrie
 
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