Don Terrill’s Speed-Talk

Several people were interested in this build so here you go. I also posted on the Bullet if you've already seen this.

I decided to do a fairly high effort 87 octane 385 cubic inch small block for my 3/4 ton crew cab shop truck. The idea was to make as much torque as possible and still keep the efficiency of the small block. The basic build goes like this:

GM block and ignition coils
Scat crank and rods
Manley pistons
Total Seal conventional rings
Speier 205cc heads
Lunati by Brookshire (the last one I have) camshaft 211º/219º @ .050", 107º LSA, .585/.555 lift w/ 1.7/1.6 rockers
Morel hyd. roller lifters
LGM shaft rockers
Edelbrock TR1yx vintage tunnel ram
Holley throttle bodies and 36# injectors
Megasquirt MS3-pro ECU
EFI connection 60-2 timing cover/ckp set

The engine made 420 ft/lbs @ 2700 rpm (as low as the dyno would hold it), It made 487 ft/lbs @ 4500 rpm and it made 466 HP @ 5500. Here are some photos of the engine and the dyno sheet. I will follow with random assembly photos.

random assembly photos

More photos........................

more photos yet....................

The last of what I have..............

Very nice! That fit under hood?

Curious how it would do with a common shelf efi intake like this.


I had this in my old street strip 383 making somewhere near 480-500 hp. Fairly cheap and simple.

Cool use of the Edelbrock Tunnel Ram.

Orr89rocz wrote:Very nice! That fit under hood?

Curious how it would do with a common shelf efi intake like this.


I had this in my old street strip 383 making somewhere near 480-500 hp. Fairly cheap and simple.

I don't know if it fits yet or not, just got it off the dyno. I've measured and it's going to be very close, I may have to add a 2" cowl hood which isn't a big deal. The mini-ram would probably run fine but the runners are very short so it would probably loose bottom end over the longer runners of the street tunnel ram. I say probably because until you test it's just theory I also know you can get runner spacers for the stealth-ram which would increase runner length and that would help a lot. Also, having the throttle bodies directly over the runners as opposed to a single front mount is an advantage because the air has to turn less.

I'm guessing yours was more of a steet/strip effort instead of a towing/hauling effort? Super short cam timing in this one

I had a feeling you would do a 107 with Chad's heads

This is exactly the sort of thing I'm looking to do for a long-bed, lifted square body but on a 496 base. Well, minus the tunnel ram, full-blown efi and shaft rockers so maybe not "exactly", lol.

Either way, I'm anxiously waiting to see what you do with the exhaust system.

Great job!

Edit: I hate to see someone start blowing holes in the "you need a wide LSA for towing torque" thing

What are you going to do for headers on the truck? Chad posted 215 for in. duration on TC. It's really 211?

77cruiser wrote:What are you going to do for headers on the truck? Chad posted 215 for in. duration on TC. It's really 211?

The cam card says it's a 215/219 which is what I ordered. It measures 211/219 so go firgure

Headers I really have 3 options. #1 Stainless Hookers 1 5/8" with 2.5" collector 4-1 design, quite small for the exhaust ports, sized about right for the power
#2 Stainless Works 1 7/8" with 3" collectors bolt-in for the truck and fit the exhaust ports...... easiest option.
#3 build a set of 1 5/8" step to 1 3/4" with the primary tube offset to the top of the port and stretched to fit the bottom.
This would be a 4-2-1 design and would make the best torque curve. This option is expensive and time consuming though.

Here is the Dynomation I ran before the dyno. I did have to fudge the manifold in this program, I think it was confused. However, good data in equals good data out!!

RevTheory wrote:I had a feeling you would do a 107 with Chad's heads

This is exactly the sort of thing I'm looking to do for a long-bed, lifted square body but on a 496 base. Well, minus the tunnel ram, full-blown efi and shaft rockers so maybe not "exactly", lol.

Either way, I'm anxiously waiting to see what you do with the exhaust system.

Great job!

Edit: I hate to see someone start blowing holes in the "you need a wide LSA for towing torque" thing

Here is what I'm doing for exhaust, I just haven't figured out what I'm doing with headers yet. Single 4" up the right side with (2) mufflers. I wanted to keep the spare tire so I kept it single.

Here is the truck it's all going in.......................

I have used that same intake on a 350 and a 355" with many carbs and different cams and it works wonderfullll'
It out powers the RPM intake when I did some back to back butt runs with a few intakes tested.

But I have noticed your top is different than the vintage one I had.. Mine was much taller making the entire intake taller than 12" by just a hair.
But I see you need it to fit in that shiny truck.

Was the placement of the injector set low on the intake for a reason?
I would think you could get the fuel atomized better if it was raised up the runner a bit.
Possibly make more TQ. I know Duttweiler raised them in High HP big injector deals.. I don't know just asking.
I have not graduated to FI yet. I still like my carbs

Question: I noticed the valvespring pics and it got me wondering about what kind of seat and open load you are using for the hyd roller in relatively low rpm application like this.