[Mr. P-Body]

One of our friends has a '78 GMC "short bed" weighing in at 4,100 and change (with him in it), running 12.20s all week on 93. His goal was a mid 12 second pickup. He has Chevy aluminum heads (late '80s Corvette) mildly ported, Comp solid flat tappet (XS274S), 6" rods and SRP pistons. Performer RPM and Hooker... He's VERY happy, and the thing is a beast. It runs well in traffic and gets ABOUT 13-14 MPG on the "open road". 406 CID.

A nice pair of iron heads would actually make more power. This combo seems to have plenty of low-end for driving, and is severely "traction impaired".

I disagree on using stock 400 connecting rods. 5.7 rods are too cheap to ignore, and MUCH better. 6" rods are better, yet. Many pistons available either way. I DO agree, no need for a forged crankshaft as long as you have a genuine Chevrolet nodular casting. We've seen many iissues with the cheap import "cast" cranks (regardless of brand). This is the single small block application we recommend a "high volume" oil pump, due to the size of the main journals (we don't use the HV pump in "race" engines, just street).

FWIW

Jim

[my87Z]

i wouldn't use the stock rods either, i was just going off of a bare bones buget build.

if he has the money i would certainly go with a larger rod, and a hyd roller cam

[blackpanther68]

Originally Posted by vinniekq2

cheap 400 I built for a friend. 1978 monte carlo, 20 plus miles to the gallon when right foot is restrained and 14.1 1/4 mile times with 2.73 gears and white wall radials.turbo 350 with shift kit,stock converter.
Bone stock short block rebuilt with cast pistons and static balanced,stock heads.Mild 430 lift flat tappet hydraylic cam,street master manifold, 625 carter carb,1 5/8 primary headers,2 1/2 " dual exhaust not mandrel bent. no where near 400 HP,but a tonne of torque. tire melter

This sounds awesome. I am building a stock 400 with a 488/510 cam and 2.73 gears and a powerglide. 750 quadrajet aluminum intake stock heads stock bottom. I hope mines sees somewhere in the 15mpg range if my right foor is "restrained".

[vinniekq2]

power glide with 273 gears will make decent power and should make your mileage easy.not sure how hard it will launch

[DOUGIEB59]

Ok, here we go... What if a fella wanted to build a 377... Winderupper!!??

[vinniekq2]

377 = smaller engine ,so less torque at a higher RPM.Its all simple math,,,start with what you want,add in what you have and see what it will take to get you to where you want to go.EG: If I have 400 rwhp in a 1970 Nova,set up with 4.11 gears,matching transmission to engine,the car hooks well( assuming drag race) has traction bars that are tune able, the car weighs 3500 pounds or less with driver and fuel,ready to go,he has slicks,this car will go 12.0s.

to figure out what your car will do,add or subtract 1/10 for every 10 hp up or down.If you use a (Winderupper} you will need gearing to accommodate the different powerband.for every 100 pounds difference add or subtract 1/10th.If your car is not as good at hooking as the nova,expect slower times.If you do not use slicks,expect 13s.If you dont need slicks expect slower,much slower.Add 3/10ths for exhaust system on small blocks.This is not an accurate guide but it will give you an idea where you might be or where you might get to with some tuning.

[stallion0606]

what could i expect from a 400sbc bored +.030 with flat top pistons. stock heads and stock rods stock crank maybe a mild cam for a 79 chevy 4x4. running 3.73 gears with 25 inch tires. i have 4.11 gears for rear and 4.10 for front but an a tight budget and never put gears in diffs. so im not real confident on installing them. any thought would be appreciated.

[stallion0606]

I ment to say 35 inch tires. I was reading earlier about the small block 400, which i do have a compllete one. has been rebuilt once, but the kid who had it spun #3 rod bearing. plans are to rebuild it again at put it in a 79 chevy silverado 1/2 ton 4x4. any suggestions on more horsepower and torque for this engine.

[6426yy]

http://www.google.com/url?sa=t&rct=j...oiJlqZq9H3h6XQ

I'm doing one of these builds pretty soon, gathering parts now.