Pontiac engine

[paint2361]

I wanted to know what you pontiac people think is a good engine combo (not LS) for street, autocross, weekend track driving...
I was thinking a 389 or 400 with a stock stroke, aluminum heads, and all the good stuff to put it together. With pontiacs already being a tall deck, I think a stroked pontiac would be too "torquie" for this kind of driving. But i dunno as I have never drivin one. whats your thought?

[Roadbuster]

For me a pontiac 455 with a 428 crank built to rev and it should be a blast. I have a built 400 in my GTO and it is a fun to drive.

[astroracer]

455 with a 400 crank, aluminum heads, RPM intake and a stout cam. Have fun.
Mark

[paint2361]

For me a pontiac 455 with a 428 crank built to rev and it should be a blast. I have a built 400 in my GTO and it is a fun to drive.

What mods do you have to your 400?

[Exiled]

455 with a 400 crank, aluminum heads, RPM intake and a stout cam. Have fun.
Mark

You mean 400 block with 455 crank cut down from a 3.25" to a 3" main correct?

If its a 400 crank in a 455 block it would need 1/4" spacers since the mains are smaller on the crank

[Skip Fix]

You need a good oil pan like a Canton or an Accusump to keep up oil pressure. ALuminum heads also can have soem potential oil drainback issues.I used a 455 for many years and it worked fine, had a broader torque curve than a 400 so you can lug it a little and be OK.

Although the 4.0 stroke motors I agree have a better street balance between the 400 and tire roasting 455.

[Yoda4561]

Getting the oiling system ready for track duty would be the biggest thing, H-beam forged steel rods and forged pistons are a must if you're going to spin the engine past 5000 RPM on a normal basis. Rest of the build will depend on what you really want out of it, a daily driver that's fun at the track, or an autox/roadcourse car that's tolerable on the street once in a while.

[Roadbuster]

What mods do you have to your 400?

Nothing much. Bigger cam. Still has iron d-port 16 heads and iron intake with a HEI distributor.

[astroracer]

You mean 400 block with 455 crank cut down from a 3.25" to a 3" main correct?

If its a 400 crank in a 455 block it would need 1/4" spacers since the mains are smaller on the crank

Yup, got it backwards, 400 with a 455 crank... Sorry
Mark

[OLDFLM]

440-stroker sounds like the perfect Pontiac combo for your wants! 400 block / 3" mains / 4" stroke / 6.8" rods / 4.185" pistons = Poncho power that revs like a small block!

Zero deck + 74cc aluminum heads = very streetable sub 11.0:1 compression and roughly 575-600hp/540-550ftlbs with good flowing (300+cfm) heads / 240/260-ish solid cam!

Average hp/tq #s from 4500-6500rpm = 500hp/500ftlbs!

[Roadbuster]

440-stroker sounds like the perfect Pontiac combo for your wants! 400 block / 3" mains / 4" stroke / 6.8" rods / 4.185" pistons = Poncho power that revs like a small block!

Zero deck + 74cc aluminum heads = very streetable sub 11.0:1 compression and roughly 575-600hp/540-550ftlbs with good flowing (300+cfm) heads / 240/260-ish solid cam!

Average hp/tq #s from 4500-6500rpm = 500hp/500ftlbs!

OLDFLM: I like how you think!

[MonzaRacer]

Sorry Pontiacs dont need or like high rpms UNLESS you buy good aftermarket rods as all Pontiacs except SD have arma-cast rods (think grenade with pin out and short fuse).
As for built Pontiacs, honestly with designe of engine,,and NO its not a tall deck,, all Pontiacs are same EXCEPT ******* 265/301 (re garbage). Not big block not small block.
Pontiacs need AIRFLOW.
400 Pontiac, well prepped crank (one I have is a 389 nodular iron/hard chrome 010/010/shot peened), good rods aftermarket forged H or I beams, if you build a lower rpm torque arm you can get 60k to 75k miles on a set of good name brand aluminum rods with zero issues if you build and drive it right. YES low rpm Pontiacs CAN run aluminum rods for miles and years if properly treated on street,, seen it and built few.
Forged pistons, square block, hone with torque plate IF you can find machine shop with one.
It doesnt take huge cams for great torque, and yes aluminum Edelbrock heads are the easy upgrade, I would not go for 11 to one even on aluminum heads unless you want to run a larger higher over lap cam. Even on aluminum if your cranking compression goes much over 190-200 you buying high octane and mixing in booster or race gas.
AND even well prepped stock heads will make ludicrous torque if you spec right cam. And as for a solid cam, pass. If you really want good driver, buy a higher lift, medium duration hydraulic roller. And since you are buying pistons,,dished ones and keep it 9.75-10.0 to 1 is about as far as I would push pump gas.
Build for low rpm torque, and flat curve up too 6k redline. No need to spin the engine.
I have pre built (desktop dyno) several combos for a few people,,,Ill see if I can dig up the results. Hardest part is getting good headers that fit right.
This is just from having owned/built/beat on Pontiacs since 1985! My last iteration was my 1969 Catalina Ventura with same chrome crank, junk armacast rods, cast pistons and 400 2bbl heads, threw in a one off lunati solid flat tappet cam, and Offy 2x4 and 2 Carters and a set of Dough Thorley headers for a 64 Tempest. Put a Vega converter behind it, 2.93 limited slip, had N50 Gillette Sprint 50s and after HARD burnout it hooked and lifted the frontend, but wouldnt idle below 1800!
Good luck