Hi all, My ‘60 LeSabre came with a basic 2bbl 364. At only 47k original miles it runs well but sure doesnt get going swiftly. They were rated at what? 210 hp? I have plans to change to a later model O.D. trans and open driveline (already have a ‘61 center section) to get a favorable first gear ratio. My question is, what can I do to get some more power out of this? Rather not transplant the heart of this beast though a late 401/425 would sure help with that and make trans application cheaper and easier.
A few items that come to mind. Get a 4bbl intake and carb, port the intake (see the doc dual place sticky), re-curve the distributor, install a free flowing dual exhaust, and ditch the fixed mechanical fan. Beyond that, bigger cam. Same items would also apply to a 401/425.
How do you feel about the self learning fuel injection setups? Is the distributor recurve some sort of kit? Does the electronic conversion do anything for recurving? Ive thought about making my own shorty headers too.
I believe the recurving 'kit' comes in the form of different weights for the mechanical advance. Electronic conversion plays no part in that. I think both Tom Telesco and Russ Martin provide a swapper (core) build service to do both at the same time. As for EFI, I've been reading everything I can find on the subject and so far it appears EFI does not provide much in the way of power increase BUT does provide great cold start, superb throttle response and improved gas mileage. As I'm poor right now, I'm holding off buying in the hopes the tech improves even more and prices drop as it becomes more mainstream. LOL Also bought a lottery ticket.
Like was said above, self learning EFI is a great way to improve economy and driveability. It won't magically increase horsepower though. A re-curve kit basically changes the springs and weights inside the distributor. This effects the amount of mechanical timing advance, and the rate at which the timing is increased from the initial setting. Bringing the advance in sooner will really wake up the bottom end. I converted to a Pertronix electric ignition at the same time, but they are two separate things. You could add headers. From dyno tests posted a while back, they don't tend to add much power though. It was under 10hp on a somewhat built 425, if I remember correctly.
Thanks guys, EFI is about cold start and drivability. My understanding is HP and MPG are not improved. Just spoke with Centerville Auto (Ron?) out in CA. He said I should switch to 4 bbl intake and Edelbrock 750cfm. 364 4bbl real hard to find - he has just one for $600! Also said dual exhaust...he has a driver side ex manifold from a dual exhaust car. Supposed to be better flow for left head but thats also rare and $495! Otherwise he suggests a cam swap as well.
Mr. Codman, are later 401/425s a bolt in as far as motor mounts? As I said I will be converting to a late OD automatic. Finding that bigger nailheads which need total rebuild go for a surpising amount! Probably just gonna stick with the 364.
Thank you roadrunnerz! Will be watching that. Another question for you all, does a 750cfm carb sound like too much? Centerville Auto guy said 750 Carter/Edelbrock. Figure this with a little hotter cam, dual exhaust. And docs intake porting. Also, the later model trans with a looser converter.
401/425 will directly replace the 364. The issue is that the crank is different on the '64 and up Nailheads because the THM 400 attaches differently. There is a way to make the later Nails fit the Dynaflow, but I have never done it. Perhaps Tom Telesco or Doc could 'splain how to do it. The easy way out would be to find a '63 or earlier 401 or a '63 425
It doesn't matter, read the post that you replied to, he wants to get a later model O/D trans anyway so if the 401/425 engines still mount the same then no problem.
I keep reading that Nailheads like big carbs - I run an 800cfm Quadrajet on my stock 401. Runs fine. But there is a Fitech in my future, according to the gypsy fortune teller
Roadrunners, do your reasearch. Ive talked to two people who have FI tech, and problems. One just shuts itself down. Both said that their tech line “help” is just horrible. One guy was just told to “read the FAQs on the website”! Check reviews. Holley has been in the fuel delivery business forever and knows customer service. Go with a Holley unit.
i don't get why a FI is such a big deal. it gives no more power then a carb and maybe less. a good carb adjusted right will start up cold and be able to drive right off. the FI will start up faster after sitting for a long time, only because of a electric fuel pump, which you can add to your carb. nothing feels or sounds better then the secondary kicking in or the second carb coming in. lol
They hold the promise of being self tuning. Im no good at carb tuning (which seems to be an art), so that is VERY attractive. And a touch of the computer age brought to an old ride is appealing to many as well. My 2 cents
As to your question,yes. Obviously if you use a THM 400 there will be transmission mount differences.
