Quote:
Originally Posted by Bobcherry13
Thanks to all. Finally got off my lazy ass (plus it was 100+ in South Carolina the past few days) and put the 35 nozzle in the front squirter and the 31 on the rear. The stumble is all but gone. I wish I could answer you guys on what type of cam lobe grind I have and such, but I am having a hard time getting in contact with the guy I bought the truck from. I guess the only way to know what I got is to put a new cam in and pull the heads to see if he did any head work. The guy said the engine was a crate engine, but did not specify wheather or not it was a long or short block. I am new at truck performance, began a motorcycle guy (part of The Jockey Journal). The truck has a turbo 400, and a 10 bolt rear-end (I know I already bought a 9" I have to cut down). The rear-end is a limited slip with 31x18.5 inch Hossier street radials. The truck will light "one" up in an instant (and hold it for as long as you got the gas down) and chirp both really good going into second. Without spending $300 on a dyno, would you guys say he may have had some head work done or is this common for this type of set up.
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You have just told me, in no uncertain words, that you may be definitely over carbed. First off the carb that you have performs really well at higher RPMs and your discussions on the daily driving talked about a BOG. So that tells me that you have helped by changing the internals, but your engine still has a little slump to it. The bigger carb will require a good air signal for performance, so the increase in the RPMs makes that signal stand out. If you take your heads off, after a period of time you will find that there will be deposits on the intake valves that is related to the LAZY air charge that you are getting and the overgassing of each cylinder. That is what happens if you over carburate your engine. Unless you plan to drive around above 3000 RPM, all day, then I would look to a smaller CFM rating and give up the TOP END reponse for the economy and lower end torque. You can confirm this by contacting ANY carburetor manufacturer's tech department and they will give you input as to what they see as a possible success path here.
Yes, it appears that you have a great "Peg Leg" tire burn and the cam and heads are the items that help in this. As for head work done, MAYBE, but many Crate Motors have a good solid flow design in their ports and it is possible that they came that way. A dyno around here runs $50.00 for two pulls and then more for tuning runs.