Originally posted by shaynet
I am considering ditching the thermoquad for a Holley 650DP or 750DP as I am in the process of a rebuild.
XA Coupe - The pump for $160 is a mechanical one. I will make enquiries and see if its fitted up for std lines or bigger.
Brenx - a 750DP is as big as I would go. My cam is a street/strip number CLH575 hydraulic from COME (if they ever get it to me) so the pump would need to feed the carbie up to say 6500rpm.
If I do need to go to 1/2 innch lines does this involve a new pick up in the tank? I've seen the line for sale but what happens at the tank?
You'll need to go electric. A mechanical pump will only fuel a good engine till about 5800.
Sounds like a 650dp would be the chosen carb but a 750dp could always be down jetted and jetted up for a hotter engine. Personally if you've got the few extra $ I'd go 750 and down jet. As I am sure you'll get bored and want more.
Who makes they CLH575? A good cam to get to 6500rpm is the Crane F238. It comes in hydraulic and also solid configurations.
Throw a Holley blue on the stock lines with a fuel pressure gauge so you can keep an eye on the pressure. If the pressures no good? The pickup will need to be changed and the tank modified with a 1/2" pickup. Most radiator places do this for around $150-$200. Otherwise Supatrik engineering.
What model car is it? In XB's changing to a 1/2" pickup in the original tank is impractical. Due to the spare wheel well.
Try the holley blue on the stock lines first. Don't spend $ unless you need to.