Don Terrill’s Speed-Talk

Got a freshen up in the shop and need some advice. This is a 408 sbm in a truck. Weighs 3550lbs with driver. Pump gas driver with iron Indy heads,3.73 gears, 4000 stall 9.5" converter . Hyd roller 288/234@.050 .565 gross w/1.6 rr,Isa 112,icl107. 1 5/8 long tube headers,32"? 3" collectors with short pipe to mufflers. The intake is an Edelbrock rpm 2 plane with a quick fuel 750 dp. It runs 11.30@118 mph which seems ok for the combo. It works power brakes,etc. Seems a shame not to get a 10.90 out of this? Things that can't be changed,gear,converter and headers. Ideas welcomed.

Knock 500 Lbs off the total weight would be a great start
More tire comes to mind as well .Fuel additives may help power

You may not have to look under the hood!
Always keep in mind that even wheels and tires are considered Rotating mass and suck up / lower HP much more then folks think !

Lighter wheels and tires can be a option?
If it has truck/ Jeep type 10 ply tires they need to go!

Motor wise with those heads and duel plane Intake and cid it could definitely make use of a 780 to 800 cfm Carb and if not that a 1" open hole spacer with or without the bigger Carb.

The headers are too small for that 408 cid in my opinion also.

How much of a freshen-up budget and how deep are you allowed to go? Lighter pistons with thinner rings are now available. Verify the static, dynamic and cranking compression. They're often lower than we'd been told.

Seems like it runs pretty good for the overall combo imo.
I’m not sure there is much of any “low hanging fruit” left.

If you’re going to try and do it on power alone, you’re looking for another 40-50hp.
I don’t see that happening from just a few minor tweaks.

PRH wrote: ↑Sat May 16, 2020 10:40 am Seems like it runs pretty good for the overall combo imo.
I’m not sure there is much of any “low hanging fruit” left.

If you’re going to try and do it on power alone, you’re looking for another 40-50hp.
I don’t see that happening from just a few minor tweaks.

Exactly what I was thinking. 11.30’s is VERY respectable especially in a truck with all the weight on the wrong end.

The low hanging fruit is the converter, gear and headers. I think with a custom spec 8" converter and more gear you would get pretty close.... but you say those are not up for change. Well if it's just for the sake of saying it ran 10.?? Why not just put a small nitrous kit in it. Otherwise put some better cylinder heads on it, and more carburetor cfm.

x2 add 150 hp shot

DeezNutz wrote: ↑Sat May 16, 2020 1:34 pm and more carburetor cfm.

yup. Especially with the dual plane.

It's just a shop truck. Not going to put more gear or converter in it. Would like to find a better header that's not custom made $$. Compression is 10 to1 measured. With business off I am likely going to race it some as it's much cheaper than towing my racecar to the track. I built a new pan with more volume,windage tray, and scraper to try. Thinking I may pull the heads and backcut the intake valves and see if I can get closer with the revised pan. Guess we'll see.

It's got a plate kit that has paid for the cost of the build. Hellcat guys seem to be learning.

What's been done to the heads already? Pulling them off simply to back-cut the intake valves doesn't seem worth the ROI.

It's just intake gaskets an afternoons work. I'm not sure if it will make a difference on the track,but both changes I have tested in the past and seen good gains. I just don't want it to be down long or let it snowball.

100 shot

Prh is correct. Nitrous is not the answer. Should be able to test next week if the rain doesn't frick things up.