305 swap

[Bamfster]

I agree, in a 400 that cam would work nice for DD duty. I run that same cam in my camaro's 350 and I'm getting 16-18 in town [yello) <-- wow, that's good mileage. [/yello)

The 600 vacuum secondary Holley I have on the 350 in the Blazer was faster and stronger feeling with the stock 66 jets in it, but with the 64's I put in it, it gets considerably better fuel mileage... and it still drives fine and pulls the trailer better than the old 305 did. I just have to wait a few minutes longer to "go" in the morning for the motor to warm up.

If fuel mileage wasn't important, I'm sure a 650 would be stronger/faster than the 600 on the 350... as would a 750 on a 400 rather than a 650. That's what makes this sort of stuff fun. You can build your junk the way YOU want it... to suit your needs (or wants ;) ).

What I found out was that the Edelbrock 600 had better idle quality, driveability and mileage than the Holley 600, but the Holley was consistently 2 tenths and 1 mph faster. I would have to venture a guess at saying that the 750 Edelbrock may be a good choice on the 400.

[truckertom21]

yah that's what i was thinking. but hey once i get that desktop dyno then I'll see what combo will work for my truck...and as far as tires go i was going to put either 33 X 12.5 all terrains on it or if those rub then a set of 31 X 10.5 and they will be on the black steel rims size 15 X 10 for the 33's or 15 X 8 for the 31
the truck is a long box so their isn't much to do with it but maybe a 2 wd lift and a good set of tires to make it look cool...it will just be a work truck none the less.

[yellomalibu]

http://www.holley.com/applications/C...bSelection.asp

Engines only need big carbs if they have big cams and will be turning high rpms.
I selected 400 cubic inches with a 5000 rpm max rpm, and they recommended carbs from 600 to 670cfm.

[truckertom21]

cool i never knew all this stuff was out their to help people out with their projects i thought it all was trial and error.
BTW...I'm having one hell of a time trying to find a set of vortec heads. I've been calling up most of the junkyards around my area (haven't had time to call all yet) and they don't have anything that would have those heads...I'm thinking that most guys who see them bought them right away...is their a head that flows close to the vortec heads in the after market?

[min301]

There are a bunch.
Depends on what kind of budget.

Scoggin-Dickey is a good source for Vortec heads.

[Bamfster]

X2 on Scoggin/Dickey. For what you will pay to rebuild/freshen a used set, you can get new from them.

[truckertom21]

okay cool i just got a desktop dyno from a friend and so i'll be checking it out...its an older version but it should do what i want it to do.

also about the heads how well do they flow? i cant find the numbers so i can put them into the dyno

[Weldangrind]

okay cool i just got a desktop dyno from a friend and so i'll be checking it out...its an older version but it should do what i want it to do.

also about the heads how well do they flow? i cant find the numbers so i can put them into the dyno

I just sent you some thoughts in a PM.

[truckertom21]

okay cool i got them i'll try that

[rightpedal]

I saw the gas mileage talk and had to speak up. Once you get the rig up and running get an air/fuel meter and tune it with that. My Blazer (350 4spd 4wd 4.11 gear 35' tire) was getting 8mpg and we got it up to 9.5 mpg with the meter. Don't laugh that 1.5 makes a huge difference.

Sacrilege coming:::::::: Don't put a big cam in this thing. It just wont help you. The blazer is on its third motor(I have owned it a while) the most recent motor was built to go into a much lighter car and has a bunch of cam (comp mag 525'/24 It was used in a fix. I gotta go wheelin. Its a lot of fun north of 4000 rpm and doesn't do a damn thing south of that.

Question how much could be gained or lost in compression with a really thick head gasket? (400/vortec)