: 472 Performance



dyess1133
08-03-04, 01:46 PM
hey i have a 68 sedan deville w/ a 472 and i was wondering if anyone knows of any in-exspensive mods i can do to improve on the h.p. or gas millage?

Shoehorn
08-04-04, 06:59 AM
It all depends on what you consider cheap. My 472 is off at the machine shop atm.

First, if your heads haven't been redone for unleaded gas, get it done.

Edelbrock makes an intake for your engine that sells for $255 at www.jegs.com. I got mine from ebay for $180.01.

Edelbrock also makes a cam and lifter package matched to that intake. If you have ever seen a 472 cam, you'd understand. It's worthless.

You can get block hugger headers for it. DO NOT buy the ones being sold on ebay by SSAutochrome. I bought a set, and they look like ass. One was so warped that I had to bolt it to a jig an heat it to straighten it.

Lose the Y-pipe and go with dual exhaust with a crossover tube.

I'm running 4" stainless Supertrapp mufflers on mine. They are loud, but very tunable. If you want to mellow it out, put a glass pack right at the end of your head pipe, then the crossover pipe, then the supertrapps. It will give it a deeper tone. You will only get the Ferrari sound when you stand on it.

The Holley analog fuel injection kits are going for 700ish on ebay atm, which is about half price. The digital version is out, so people are less interested in the older analog control.

Here's a really cheap one. Pull your points distributor. Throw it in the trash. Buy a HEI/vaccume advance distributor off a 70's model. Points suck.

A roller timing chain will save you a couple HP.

Btw, I'm doing all of these things, and it's going into an 87 Fiero GT on a THM325-4L trans from an 85 eldorado. Really easy do do actually, if you can weld. The Fiero's engine rides on a subframe that drops out the bottom. This engine is a bit too wide, so i will have to use coilover struts, and modify my strut towers.

dyess1133
08-04-04, 11:41 AM
thanks for the info. how much did it cost for you to get your heads done for unleaded?

caddycarlo
08-04-04, 12:07 PM
caddy heads don't need to have this done they are hard as rocks ... just have the seats cut

dyess1133
08-04-04, 09:52 PM
Carlo, What Do You Mean By Have The Seats Cut?

Shoehorn
08-05-04, 06:13 AM
I don't really know how much of it is head work. It came to about $400 that I don't have to pay till I pick it up for all the work.

This car is probably going to kill me, but after all the work I'm putting into it I will have about 1:8 HP to weight, and 1:5.5 Torque to weight. Those are evil numbers. It will go fast in a straight line, but with about 500 extra pounds in the rear, it's gonna handle like a pig on rollerskates.

caddycarlo
08-06-04, 12:26 AM
the convertion is to put a insert into the head so you have a harder surface for the valve ...... that is not needed just have a regular valve job done and it will be fine ......

Cygnus x-1
08-10-04, 11:00 PM
A little FYI for those who are doing an unleaded conversion on their heads - I have heard from many sources that hardened valve seat inserts have a bad habit of coming loose from the cylindar head with tragic consequences. I chose to go with stainless exhaust valves and hardened intake valves. The valve set ran around $200 and requires no major machine work. The motor is not back together yet, so I cannot guarantee success. As far as NOT converting to unleaded, I tried that trick an ended up burning two valves. A 472 running on 6 cylindars isn't any fun.

lux hauler
10-21-04, 08:16 PM
A little FYI for those who are doing an unleaded conversion on their heads - I have heard from many sources that hardened valve seat inserts have a bad habit of coming loose from the cylindar head with tragic consequences. I chose to go with stainless exhaust valves and hardened intake valves. The valve set ran around $200 and requires no major machine work. The motor is not back together yet, so I cannot guarantee success. As far as NOT converting to unleaded, I tried that trick an ended up burning two valves. A 472 running on 6 cylindars isn't any fun.
I've heard that it's not recommended to re-use old valves. Could that have been your problem?
I've heard, from more than one source, that hardened seats in 472/500 heads are not needed. Found that out after I had mine done. :rolleyes2