Good day,
I am needing some insights and opinions about a couple options I have available to me that could improve performance of my 1957 GMC 270.
Currently it is in stock configuration and it is very tight with good compression, clean burning, with smooth idling and acceleration characteristics. Therefore a rebuild is not necessary.
I want to improve the hp for pulling and towing. I plan to install a 5 speed overdive transmission (NV4500) to keep up with traffic on the freeway.
However I plan to install this motor in a 3/4 ton truck and I would like to improve its performance and keep the costs within a limited budget.
Modifying the cam and having a mild 3/4 grind done to it is a given. In addition dual Fenton exhaust manifolds are a given.
My options and questions are these:
- Use of a civillian GMC 302 intake manifold wih either a 2 barrel carb or 4 barrel carb ?? - what is gained and what is lost should I choose a 4 barrel carb over the 2 barrel? Is fuel econmy reduced with a 4 bbl and the 2bbl may be somewhat more frugal on gas consumption?
Can someone venture a guess and provide an estimate of performance values between a Dual Carb Intake setup vs. a 2bbl and 4 bbl carb setup should I use my civillian 302 manifold?
The head on the 270 is the standard 819 Head. I cannot afford an H-Head. Am I right that a 302 - large port 983 head would not improve performance on the 270 block? Is my understanding correct that there would be a loss of compression with a 302 head on a 270? The 819 would give me what I want; a smoother idling motor...as I understand. Correct me if I am wrong.
What can I expect the cost to be to install larger intake and exhaust valves on the 819 Head?
Your assistance and knowledge would be greatly appreciated.
Thank you in Advance.
Tom
