Guideplates and Carbs.

[Spanish Dave]

A couple of bits of advice needed here

1. Is it OK and advisable to use pushrod guideplates with rail type rockers. I have scew in studs and the pushrods are hardened. It is just that the rocker arms seem to have been rubbing very slightly on the studs at the base so I thought guide plates may help stop this. All the parts are new and the rockers are the roller tipped variety.

2. Would this carb be overkill for my engine ... holley 750 double pumper ... the engine is rebuilt 289 with 9.6 compression 351W heads, Comp cams 280H cam, headers with 2.5 inch collectors and dual exhaust. Weiand stealth intake. At the moment it has a 600 holley with vac secondaries.

Any help appreciated

 

[D.Hearne]

I wouldn't use guide plates with rail rockers. Where did you find roller tipped rail rockers ? If you want to avoid the rockers rubbing at the stud, then take them off and open up the stud slot in them . Also that 750 carb is too big.

 

[taylor4g63]

yeah a 750 DP is gonna be too big for ur engine. A 750 vac. secondaries however would be fine, but i doubt u'd see a worthwhile power increase over what u have now.

I thought u were always suppose to use guide plates with stud mounted rocker arms??

 

[Ronstang]

Use either guide plates or rail rockers but not both and a 750 carb, even a vacuum secondaries, is way too big for a 289....stick with a 600cfm for best all around results.

 

[Spanish Dave]

I wouldn't use guide plates with rail rockers. Where did you find roller tipped rail rockers ? If you want to avoid the rockers rubbing at the stud, then take them off and open up the stud slot in them . Also that 750 carb is too big.

The roller tipped rail rockers are from Comp cams ... I realise now I should have probably gone for full roller rockers with guideplates. I kind of thought that the carb would be a little big, but my pal has just taken it of his corvette and offered it to me for next to nothing. I may buy the carb for some future project as stuff like that isn't readily available here in Spain.
What would you use to *open them up* ?? File, Dremel or something.

 

[D.Hearne]

Use a dremel tool. They shouldn't be rubbing though, unless you've got maybe 7/16 studs and the rockers were made for 3/8 studs.