Rochester vs Holley

[Renn Sport]

So... my 55 Chevy is running like spluttering mess. To be fair for a car that so old running the original engine and drivetrain its pretty good going really.

Next year I am going for a LS engine, box and axle conversion so I would like to remedy the situation inexpensively. I had a 68 Mustang and ran like a dream so I now whats possible in terms of smoothness.

I'll give cleaning the jets out another go...


So choice 1.
Have the original 2 barrel Rochester refurbished to like new. £150 + postage + parts £200 maybe £220

choice 2.
Spanking new Holley 600 cfm electric choke carb from the states on an adapter plate £220 + Shipping + duty and + Holley air-cleaner £250 all in??

What do you knowledgeable chaps think? Just go for the new stuff? Or keep to the old?

Just want a smooth running motor for this year and maybe next before the LS project really ramps up.

[KevinCamaroSS]

Have you any plans for the old engine? If so, then keep the original Rochester, if not, get the Holley.

[Matt Harper]

it's not a "Power Pack" or "Super Power Pack"? Just the base 265ci?

That being the case, I think a 600cfm 4 barrel will over-fuel it. I'd stick with original and rebuild the Rochester 2bbl. Are you sure the rough running is down to fuel mixture/delivery?

I would be equally suspicious of the ignition system/timing.

[Renn Sport]

I have no plans for the original engine. It would be nice to keep it, or put in in something but alas I think it will end up on eBay.

Originality only matters so much as from the exterior and interior, I would like the car the car to look a stock as a rock apart from the mild lowering, and the soon to be added American racing torque thrust wheels. Under hood is a different matter, however as modern engine steering and brakes are all on the cards. Even a mild LS will prove so much better to drive than the original lump.

As far as the Holley option, I have been in touch with Holley and they assure me this carb is the absolute base model, which is designed for stock engines. Its not an avenger or a double pumper... just there bog standard job jetted for street cars. The only technical or performance advancement is the 'electric' choke!

I am umming and ahhring over this... think I may go for the holley. Not sure the Rochester is worth messing with.

[Northwestel]

Go for an Edelbrock, Holley are tts to tune, failing that re-build the carb. I'ts pretty easy I can help you.

Rough running might be:

Fuel pump / Jet in carb / Float

Edited by Northwestel on Tuesday 29th August 14:48

[Total loss]

Has your 55 ever run smoothly? if so & now it doesn't, then only the points or cam lobes would have worn out since assuming like most you only do 1000 miles or so a year, every thing else that could cause it would just be out of adjustment & just need tuning.