Jolly Green

IF you guys had a choice, which engine would you rather have?

The 67 425 or the 68 455 and what heads would you put on it?

And would you rather put stock heads on it port/polished, or Edelbrock Performer heads?

Olds64

I would rather have the 455. I am building a 455 with C heads. Edelbrock heads aren't worth the money for a street car. Stock heads can flow just as well.

Jolly Green

I guess I should also throw in a question that's bugged me for a while. What do you think is a good hp range for a powerful streetable car? For street and strip? Not straight dragster.

Olds64

Horsepower doesn't rule the road, torque does. That is what gives you that "seat of your pants" feel whenever you step on it. If you make less thank 500 ft. lbs. of torque with a 455 then something is wrong.

Jolly Green

Haha, DANGIT, I always need to tweak my posts. Ok, what horsepower AND torque ranges would you think would be best in that case? I like the 500ft-lbs.

don71

I would go for the 455 and all its torque.

Its possible to spend a lot of coin on the factory iron heads. Sometimes the machine work and parts could could add up to the cost the E's. Your budget would best speak to that. The Edelbrocks save you weight right out of box with a little better flow. So, you decide. If you had to go cheap, then do the factory heads.

Personally, I have had my 455 for 15 years, and its great with its low end punch. It will move any land barge and drag a stump or two.

I'm about ready to step up for more flow and more rpm capacity. So, with that said, I'm ready for a 425 that would be capable of more rpm and some heavy breathing that the 455 just isn't designed to handle. Besides, it would handle the new rear I have which just might end the life of my 455.

70Wcars

455 with iron heads if on a budget...Edels require some port work to be much better than factory and this can get pricey. don71 is right about heavily worked factory heads approaching the cost of Edels. My Bracket car has gone fairley quick with C heads running the smaller 2 " intake valves ( lots of low end )
Spent my limited funds on cam and carb, Trans and converter and rear-end...also suspension work to make it all stick to the track.

Power and torque numbers will be most affected by cam profile and that can be limited by many factors ( power Brakes come to mind ) More info on your proposed combo will help us point you in the right direction

Danny

Jolly Green

Alright, here's what I propose in the long run.

Looking for a good street car that I can have fun tuning and driving on the strip from time to time. I love torque, am a light-to-light guy. Auto transmission with a dual gate shifter (hurst), tubular suspension, power disc brakes and steering, electric cooling fan, A/C (sorry, its Nevada and freakin hot), stock interior.

Oh, and another thought. I have a guy in my unit with a 02 Camaro SS...and he's a jerk...so guess what I want to destroy.

70Wcars

Would you be willing to install a higher stall converter ? Also what rear gear ratio do you plan to run? Headers or manifolds? Got some proven combos in mind, let me know some more details .

Danny

Jolly Green

To be honest, this being my first musclecar, I'm not sure all of what aspects I need to touch. I'm still learning about stall converters but I don't think I'd be against upgrading. As for headers or manifolds, I'd probably install headers eventually. Rear gears, its stock right now. I'm still a lil light on knowledge in the rear area. I'd like something that will kick me in the pants on take offs and gear shifts, I don't plan on taking long roadtrips but "ok" gas mileage would be fine with me.

Olds64

Don't forget to modify your transmission too. Do you have a TH 350 or 400? If you have a TH 350 you will definitely want to beef it up to handle the torque of a big block. If you have a TH 400 you will probably want to at least install a shift kit and aftermarket stall converter.

Jolly Green

I think its a TH400 due to the shape of the pan. Haven't gotten it out of the car yet so I can't be sure.

Olds64

The TH 400 has an S shape in the pan. The TH 350 is a square with a corner cut out of it.

Jolly Green

http://www.chevcarclubvic.org.au/tec...tification.htm

According to this page, my tranny is a 400. Came backing a 455 Olds engine that wasn't original and the vin has been partially sheared off so...

What would you suggest I back my 455 with, or if I get a 425? Upgrade to a 700-R4? Leave the 400?

What's the stock stall converter rated at anyways? For a 71 455 with 400 tranny?

Olds64

Stock torque converters are rated at about 1300-1900 rpm. I suggest you keep the TH 400. If you want to improve your transmission you can at least put a shift kit and new filter in it. If you want to do anything else you will have to either tear apart the transmission yourself or buy one from an aftermarket company.

70Wcars

You have had some great replies about staying with the 400 Trans. Good shift kit and about 2500 stall to get the most out of a street performance set-up.

I have built the following combo for a friend who is runnig a 1970 442 and has run best of 13.41 on street tires with only 3.23 gears and stock converter, more tuning yet to come.

Blueprinted Q-jet ( by me )
Edel. Performer Intake
214 In. 224 Ex. at .050 cam
Stock E heads with 2.07 Intakes and multi angle valve job
PN 2323 Forged Pistons with Speed Pro Moly rings
Cloyes timing set with cam @ 2 degrees advanced
Melling HV Oil pump with stock 455 pan
Hooker 1 3/4 " headers to 2.5 " exhaust with Flowmasters and full tail pipes
M/T Sportsman Pro 26 " by 10 " tires at the strip...T/A radials for cruising
HEI Dist with advance curve set for all in by 3200

We are adding a Daeco 2500-2700 stall Converter and more cam this winter...car should see 12.99 in good air.

This car runs on all of our club cruises and even gets driven to work from time to time. Probably 5000 miles a year and really pulls strong on the street!

Just some suggestions and I hope they are helpful.

Danny

Jolly Green

Guys you are really helpin me out, thanks! I think I'll stick with the 400 for now, look to upgrade my stall converter to 2500-ish, and put a shift kit and rebuild into the 400.

Can anyone point me to a website that has the gearings for the TH400? I was gonna try and calc RPM's at highest gear for highway speed.

don71

Try this one: http://www.idavette.net/tech/ratioc.htm

Or: http://www.bgsoflex.com/speedo1.html I used this one calculate a new driven gear (speedo) for my 400 when swapping in a 3:23 in place of my 2:56 rear.

GoldOlds

I THINK the TH350 has 12 bolts holding the pan in place while the TH 400 has 13. Or maybe it's 13 and 14 . . . either way, the TH400 has one more.

- GoldOlds