Hey guys, looking for some input on a torquey 440 street combo I'm putting together. I've been accumulating parts over years for a build that maximizes low end torque, so I'm hoping that it can be fun mated to a 4 speed with a low final drive ratio.

Problem is, I'm starting to worry about detonation and driveability, even with a motor that might approach 400 ft-lb at the crank by 1800 rpm. Basic requirement for the build is that it will run on pump gas.

440 motorhome block (1973), +0.030"
Steel crank, set up for pilot bushing
Reconditioned stock rods (ARP hardware)
Speed pro 2355 pistons, zero decked, (7 cc valve reliefs)
Engle k56h hydraulic flat tappet, 224@0.050", 0.510" lift w/ 1.5 rockers, 110deg LSA
Performer RPM/Holley SD intake
Holley 750 DP
HP Manifolds or 1 3/4" primary headers
0.039" compressed head gaskets

With my stock 902 open chamber iron heads, assuming a 92cc chamber volume, the static CR is just over 9.4:1, and the dynamic CR is 8.0:1 at sea level. There would be no quench to speak of.

If budget allows, I'd like to get a pair of sidewinder heads, which would give a static CR of 10.1:1 and dynamic CR of 8.6. Would end up with a decent ~0.040" quench distance.

I'm hoping to mate this to a trans and rear end for a low final drive ratio. With all that torque, should be able to have the best of both worlds when it comes to in town driving and low highway rpms.

A familiar option is a standard 833 with a 3.23 rear gear, with 28" tires that means cruising at 2500 rpm at 65 mph.

Another interesting/crazy? alternative is to use a late 833OD gearset in an iron case (avoid the countershaft problems of the aluminum case ODs), and a 3.55 rear. The granny 1st in an OD would take off from the line like 4.10s with a standard 833, 2nd would be similar to the aforementioned 833/3.23, 3rd is direct drive, and OD would keep a low 2000rpm on the highway. With street tires and staying off the track, I wouldn't worry about the tranny surviving.

Thoughts?

You can go with a thicker head gasket if it worries you, since you have no quench anyway. I would run it and try it. Keeping the engine and intake air cool would help a lot. I don't see a problem with either of your transmission choices. Also, you can use the aluminum case 833 if you have the case bushed where the counter shaft hole is.

I have almost the same exact combo with these exceptions:

Engle 238 @ .050, .534 lift hydraulic cam
850 Holley DP
1 and 7/8" Headers.
452 heads

I run on California 91 octane pump gas, drive it on the street and race in the 1/8 mile all the time with no detonation.

I think compression is OK for pump gas and either trans/rear combo should work well. You will probably need to do some tuning of the advance curve for best performance w/o ping in the 1500-3000 RPM range with the extreme low RPM torque. As posted, if compression turns out to be a bit too much, a thicker gasket would fix it but I guess you will be OK.

It would even be a nice runner I think with the OD transmission + 3.23. You will have the torque to handle it and nice for long road trips.

Thanks for the input guys, I guess I'll soldier on and let you know how it ends up!