408 build Throttle EFI Questions

[rcmbronc]

Putting together a new 408. Motor will be roller block with an Ohio crankshaft forged rotating assy. Edelbrock Victor Jr heads with about 10.5 compression. Hydraulic roller cam (not picked yet). Was going to use Edelbrock Pro Flo EFI but can't bring myself to EFI I can't laptop tune. My last 427 had a Haltech 2000 ECU which was great but want to try different this time.

Going to try the new Holley Terminator X Max ECU that will also control my 4R70W. Looking at using a Edelbrock Victor JR single plane intake. Was going to use a 1000 cfm Holley 4 barrel throttle body but thinking about maybe a intake elbow and a single blade throttle body. Might be better top end air flow but to me the progressive throttle blades on the 4 barrel throttle body would be better down low. Anyone have experience with both? Also what size single would be used to compare to the 4 barrel? 105mm? 92mm? 95mm?

Also thinking about the Holley Hi-Ram EFI intake. Says rpm range starts at 1500. Not sure I could even fit it.The traditional looking side mount throttle body intakes do not work well at all on my truck due to lack of room with my shock hoops. I know the 4 barrel throttle body fits well.

 

[pcf_mark]

Single blades are nice but you need a progressive throttle or it can be both tricky to tune tip in and tricky to drive with dexterity. Otherwise airflow is airflow the engine and ECU don't know the difference. You can get some monster single blades that include progressive linkage so you can get what you want / need. That HiRam looks like a beast. If you can package that I would use it because of the long intake runners build torque but the huge plenum gives you top end.

If it was me I would use the Holley throttle body on the Victor Jr intake that matches the heads. In either case you are going to need to sort out a decent air filter set up.

 

[68ford]

Buddy just had Patton racing engines built him a 445 SBF with equally as large of heads and Victor manifold with port EFI. Same compression as you. He runs a little over 90 degree elbow and large single 105mm throttle body. It runs amazing at all RPM. It makes 500ft lb by 2700rpm with a peak 615 ft lb. 680 HP at 6800. It does however have a very large cam. Very rough idle at 1200rpm and still "loping" at 2000 RPM. Very agressive but runs awesome

 

[nvrstuk]

Hope these pics help a bit... 460sbf, SEFI, Edelbrock SuperVic intake, largest elbow I could fit w/o hood clearance issues (ProFlow hood), 80mm TB, made my own linkage for as smooth a throttle tip in as possible for such a beast. Remember, a 100MM TB opening lets in a TON of air when you barely crack it open compared to let's say a 4bbl style that opens two small venturis then progressively more till all 4 open...

Works great, I wheel a lot and my throttle tip in is much smoother now than with the same TB but designed differently.

600HP/710ftlbs torque...plenty of air with an 80mm on a 460cube sbf

 

[nvrstuk]

Couple pics...lots of cleaning up to do in the engine compartment but thses are fitment pics...

 

[nvrstuk]

Here ya go...sorry about the 90deg rotation issue... it views the same on my phone as the 1st pic.

 

[pcf_mark]

^ WOW! That is a nice package.