Best engine build for my wagon

I know this is a broad topic. Funds, expected performance, real performance, and driving habits all play in here. But here goes...I want to go big with a 455. A not so mild cam, solid bottom end (forged H-beam rods, balanced assembly) good flowing ported heads, etc. I've been reading and learning though that a 400 built the same way can be a better alternative and maybe cheaper to build. What I'm fishing for is head casting numbers to look for, things like that. I've heard a regular 2 bolt main is good to 600hp I'll be well below that. I want to get over 400hp. It won't be a daily driver, just a weekend gas guzzler. I'm trying to get the TH400 I had built for it 14 years ago (never installed, just sitting in someone's shed) and I remember 3.55's were said to be a good all around street ratio. So give me you input and guide me down the Poncho path!

Thanks!

 

There are a number of Pontiac engine builders out there. I'd go there for advice. Here's one that certainly has some credibility....

http://www.butlerperformance.com/products/engines_assemblies/enginemaster.html

Lotsa information on their website....


Marshall

 

I put a 71 455 poncho in my 75 buick estate with i belive the factory ratio is like 2.94 liked the 3.23 better tho in my olds. touch above mild cam edelbrock rpm performer intake, edelbrock 600 cfm carb but definatley going back to the factory quadrajet or getting a bigger edelbrock. It still screams for the size of the car. and with the Q-jet rebuilt it will run even better.

 

I had a '66 Chevy Caprice Wagon with a 327 and a 625 Carter square bore. A fresh Tune would give me 12 mpg, after a couple weeks, 10 (maybe) until my next tune. The Quadrajunk has really small primary's and giant secondaries (as we all know) which might be good for putting around and then nailing it to eat that new Mustang. How is a Q-jet tho with a sorta hot street engine?

 

maybe you wanna think about an overdrive tranny as my 59 with a 350/700r4 knocks down 17.5 mpg consistently

 

.....my opinion why waste money. Todays gas at the pumps is crap. So you build up a engine and can't feed it right. Keep the 455 stock, the older the motor the better for power as they had more compression ratio. If anything, then maybe just add a set of headers and something like a Holley 800 mechanical spread bore carb. But the factory Q-jet will work just fine if rebuilt right. If you like to street race a little and don't really care about fuel milage on the highway then change the gears in back to 4:11. You'll have lots of jamb , poorer milage but the stock motor will run fine and not give any headaches. I just don't think sticking a bunch of money in the motor is worth it . Don't read too many hotrod magazines !!!

 

How much moolah you have budgeted for this baby?

 

I was thinking a Tremec 5 speed, but then my old TH400 showed up. It has a shift kit in it, 33 tooth steel sprags and a lot of other crap I forgot they did to it. What about one of those Gear Vendor's gear splitter thingies. Anybody have any experience with them? I've read a few articles and they seem pretty cool and tough enough. I'm not gonna race this thing, so I think I'll just do a 455 but take my time and balance it and all that. Some good ported heads and headers. That should be plenty to push around a 3600lb wagon no?

 

Are you a member of the performance yeara pontiac forum? The guys there may be able to help point you in the right direction and have what you need. There aren't many engine builders that really who know how to work on Pontiac engines so be wary of that, usually that's all they do and have long waiting lists. The things are always being messed up by prima-donna engine builders that think an engine is an engine is an engine.

The LS engine is the way to go these days and there's tons of info on how to do them and lots of aftermarket parts available for the swaps. Not cheap but if you do the math they're the best bang for the buck in the long run.
Otherwise... three deuces and a four speed, and a 389.

 

All 455s are smog engines produced to overcome the loss of horsepower caused through adding emission-reduction components and de-tuning. They are simply stroked out 425s and 426s which were peak horsepower year engines meant to be installed in full-sized vehicles.
One of the disadvantages to using a 455 is that you're working with an engine which is by no means oversquare. The longer stroke will produce higher piston speeds, thus wear. The other disadvantage is that a long stroker cannot rev as high as an oversquare without costly modifications.
The 400 cid which was originally offered in mid-sized cars were more than enough already: http://www.youtube.com/watch?v=vPFTFsL1uzk Therefore, you'll have a difficult time keeping your wheels from spinning, using the 427/426 versions., Problem is, they are not as plentiful as the 455 available

 

i liked the poncho engine simply because of the power and tourque. In a smaller lighter package/block. And i know it will run better with the Q-jet rebuilt correctly. the edelbrock is ok but it doesn't "breath" quite good enough.


i will NOT use a holley carb i traded 2 new ones for 1 new edelbrock i have NEVER had 1 that worked right,always run way to rich for my taste

 

Hmmm 455 smog engine, built to overcome restrictive emission controls the EPA was steadily adding. 400 a better all around engine, but harder to come by and more expensive. Think I'll go join that performance years Pontiac forum and see what they say also. I had a lot of ideas kicking around back then and still have them but I'd like to know what options are better now that it's 15 years later...thanks for your replies! As soon as I get it home I'll post pictures!

 

round here 400's are way cheaper than 455's
if u can find either one

 

A heavy car needs torque. Cubic inches= torque.
Why build a 400 when a 455 is stronger out of the box? No need for a wild cam or high revs.

 

Back in about 1975, Buick did a mileage comparison run, LA to New York. They picked two LeSabres, equipped identically, except for the engines. One was a 350, the other a 455. Both were the same colour so the test drivers could not see a difference. The 455 returned better fuel economy than the 350 because of the extra torque.