Thomas CV8 rocker arms

I have a set of new Thomas CV8 rocker arms. Don't know what they fit. Little Wing thinks they are Chevy V8 but I have never seen a Chevy V8 with a rocker shaft. These have a 3/4 hole for a shaft and there is 16 of them so they are for an eight. Need expert input.

Thanks Gary

 

Thomas did make a shaft rocker arm conversion for the SBC when it first came out, and some of the "experts" thought that the ball stud rockers that they came with would never work for performance use.

 

Caddy rockers are C 8,,,They could be for a completely different motor ,,but i do know they made em for the 6 cyl...Though I said I thought maybe 6 cylinder

 

these are the thomas I6 arms.. would think its the same for 235 and 216

 

The plot thickens

 

well, the measurements come out to within hairs of what my stock Olds rocker arms measure too. 3/4 shaft bore, and 2 1/4 from center of valve pad to center of push rod seat

 

are pontiac rocker arms roughly the same as the chevy ones? if so that will tell us right there if they are similar in size to what would be in one of those SBC kits (i have a 60 poncho sitting in my spare room in the apartment.. seriously... i will go measure.. lol)

 

ok so i did, and barring that chev rocker arms are pretty much the same size as the poncho ones.. heres what i found... (remember the measurement of his CV8 arms are virtually the same as my stock Olds ones are as far as length and rocker shaft bore)



virtually identical in length (center of valve pad to pushrod center), i know it looks a little off but remember the Olds arm is sticking up so it kind of skews the view a little, you have to see it in person to really tell how scary close they are!

here is what a "new" chevy shaft mounter rocker system looks like...



heathen, i guess people never really got past the idea that the stud mounted rocker arms weren't sufficient! they have these for every damn American motor and thensome!

 

look at the billet rocker arm just above... then look at the CV8... strikingly similar in shape... CV8.. CheVrolet 8????? idk.. this is running through my head like a friggin conspiracy theory lol... did i find the magic bullet??!!!

 

Somebody has got to have the answer.

 

Bushing ID looks to be roughly .750

 

Those are the sbc conversion rockers. Without the shafts and stands, I don't know what you'd do with them, other than attempt to use them on some other engine if they're close enough.

 

i had a set of those in the early 60s. they were to replace the "press in" studs on the 265 &283 chev motors that pulled out when strong valve springs and high rpm were used. you had to tap the stud holes for the mounting bolts that held the blocks on.they were hard to adjust and a pain in ass to use. the kit came with valve cover spacers to raise the valve cover for clearance. big bucks. and then good old GE started makeing screw in studs!happy days.

 

I guess you just don’t want to read it

 

I've got 2 sets new in the box for GMC 6's..... never used them because I made my own roller rockers. They made them Hy-Lift by shortening the push rod side and would work with the stock "spindly" push rods. To use 3/16" tubular or larger you needed to make the hole on the head bigger at least on the one side.