Toyota h8r

HI all, its hair pulling time for me and im wanting some advice/insight on my 85 trans am. I have a decent 327 sitting on the engine stand and everything to drop it in place of my LG4.


Now, on the other hand, i have a 454 BBC in a 4x4 i dont drive anymore and the motor is freshly rebuild with a cam. My friend is parting his BBC 3rd gen camaro and has the headers priced decently.

So.......what should i do?

Go with the 375hp(estimated) 327SBC

or mild 454BBC(mind you spun 35" mud tires over and then hooked and exploded the rear end


So the proverbial question....SBC OR BBC?

five7kid

iTrader: (14)

327:
Pros - Basically fits in place of the 305 (depending upon what heads are on it).
Cons - 375 HP wouldn't be all that street-friendly.

454:
Pros - 375 HP would be tame.
Cons - Heavier, more difficult & expensive to install, need cowl hood.

Toyota h8r

the 327 as is is dumb'd down from last time dyno'd....ran 410hp

previous owner had 2.02 heads and bigger cam(2x hump and a comp 292H setup)

ive got 083(L98 tpi heads) and a summit 1103(IIRC) cam


either way im building a car to see little track time but yet can rip the track up if needed

the 454 is running mystery "rv cam"
http://www.youtube.com/watch?v=I6r2s_uXCLc
my motor....including exhaust leak....needs better carb also

SOOOOOO...i have no clue what hp/tq the 454 would be turning

Toyota h8r

okay...this is old pic of the motor....(yes...i need roller rockers...they are coming lol)

from what ive been told...a vac secondaries 600cfm carb would be ideal for my 327

ALSO....i forgot to mention the 327 is really a 333ci due to bored .040 out and has been "zero decked"

nhrata

I would stay with a small block if it was me .. big blocks fit tight in there and there not to fun to work on

Atilla the Fun

I'd ask about your transmission. Manual transmissions tend to be herder on rear axles than automatics. Manual with 454 probably equals bye bye stock axle. Unless you like babying it. An aluminum flywheel would help.
Also, do your plans include drag radials, or drag slicks? That 327 will want more rear gear, while the 454 will do better with a 2.73-2.77:1
Then, are you gonna get used to 375 horses and get itchy for 500? Way easier to do, and to live with, if you choose the 454.
Canyon carving your thing? 327, obviously.

Toyota h8r

tranny selection based on engine chioce:

327sbc = muncie or super T-10(4spd)

454bbc = th400

i want something streetable, but yet can tear up the road if i need it.


Believe it or nopt, changing plugs/wires on buddies bbc iroc wasnt that hard

Atilla the Fun

Then I vote neither engine, as none of your transmissions has any overdrive or any decent first gear. Yeah, the 454 doesn't need much first, but even a 2.73:1 gear is too much rpm at cruise for that engine. And even an XE274 cam could run a 5-speed.
It's not as if you can't get a strong enough 5 speed or auto with overdrive. I'm assuming you already have several old transmissions.
The Muncie will call for at least a 3.73:1 gear due to it's crappy first gear, even the M20, and your 327 with an XE274 could run with 3.08:1 gearing.
Are you in a place where the highest speed limit within 50 miles is 45 mph?

AlkyIROC

Why does everyone assume an OD is required. GM produced many muscle cars over the years with just a TH350 or TH400 transmission and they were fine to drive across the country. Very few cars had gears deeper than 3.73 in them. Trucks did but they also had taller tires.

If you keep the diff gears in the low to mid 3.xx range or put a 28" tall tire in the back, a non OD transmission will work fine.

jstoltz

iTrader: (16)

I would go with the 454 if it was me. I have to get some things done and more cash and that is what I am doing. I was supposed to swap a Spohn torque arm and X member for some bb swap headers but the guy never sent the headers so now I have to get the time to file a small claims suit on him( kind of sucks I am in NW ohio and he is 4 hours away in IN) but if you can find a gear vendors setup you are in better shape than most on here with the 454 and th400. that will make it streetable as long as the rear can handle it (9") then you can actually have some real fun.

89importeater

i agree with stepehen about the overdrive thing. overdrive trannys havent been around from day one so if people could run without them back in the day than why couldnt we do it now. also i have heard the bbc is actually easy to work on in a 3rd gen. this is just second hand info. but i dont know how you figured it to be harder.

Irockz

iTrader: (1)

Funny thing is,my Iroc with a 468BB,TH350,and 3.73 gears got drove up and down the interstate on a regular basis.Good thing I didn't know I had to have 2.73 gears or an overdrive.
----------
To get back to the subject,after more combinations of SB in my car than I care to remember,I was happiest with the mildly built BB.It was just as fast,handled as well,and was more drivable than a sb of similar hp.The swap is tough,but it's not near as bad as those who have never done it would make you believe.

Toyota h8r

okay, time to stir the pot even more....

the guy who wants to sell me the swap headers is willing to trade the mild 327 for his 438BBC.......

it has a bad block(crack in water jacket from freezing once)

BUT, it has forged pistons, good rods, steel crank, worked over heads/ soild lifter cam/ roller rockers/ stud gridles,

NOW, from what i have toyed with in past...i could use my good 454 block and drop the goodies in it after boring it out .030 out.

So full blown race BBC(11.5:1 comp ratio) or save up and build more adgressive 327(afr heads and yada yada

oh btw, im settling on a th350/th400 setup with decent converter/3500rpm stall/ 3.73 gears.....can i expect a decent car?

Lastly, the 327 "dropped" into my hands.....so i dont have the funds to build uber 355 or 383 lol

AlkyIROC

Without a parts condition guarantee, I'd pass on the cracked block. You have no idea what else may be wrong. An engine that isn't running isn't worth the parts that are in it.

You said you wanted something streetable and now you're considering a race engine with 11.5:1 compression?

Toyota h8r

Well, i wanted a streetable car when the options where only a mild 327 or mild 454......

the 427bbc(bored out to 438) runs and drives....but it drips barley out of the block.....the thing sounds wicked....but he cant keep it cooled. I think its due to the cooling system not being able to be pressurized and stock raditor.


i honestly am just thinkin about buying a set of AFR heads(along that idea) and building a nasty lil sbc.......

big monster BBC sounds cool.....but only if i had a 2nd gen camaro would i build a bbc for it.


so what can i do to make my 327 more potent?

mods so far:
-zero decked block(pistons are flush with block face
-flat top TRW forged pistons .040 oversized with -5.4cc valve relife
-shot peened lt1 rods with ARP bolts
-scat steel crank
-1103 summit cam

TEMPORARY parts:
-L98/083 heads(Lt1 springs)
-.039 compressed thickness felpro headgaskets(want .028 gm ones)
-1103 summit cam lol......lookin at a 292H comp cam( im not sure on what one to go with)

the guy i know has a 292H in his 355 and hes going with bigger can abd offered me the comp 292H for 150 dollars with better springs/lock/retainers and such.

Atilla the Fun

Thank God we're allowed to disagree. If you ever have even one good experience with switching to an overdrive, either you or the moderator, you'll never go back. There's no point. Going back means giving up acceleration and gas mileage and engine life and, sometimes, the ability to hear your stereo and/or your passenger(s). But it's your car and your money.

Toyota h8r

well.....seeing as ive had 2 700r4's built(by two different shops) and they have failed....behind mild 305 lb9's. I have NO FAITH it the gm overdrive trans......hell my dads 2001 xtreme(4l60e) has spit a trans out....with stock 4.3L

Atilla the Fun

I've failed fully 6 different 700R-4s myself. The one that still hasn't failed is a level 3 from www.700r4.com. Is worth your time to take a look, and read what makes it a level 3. Rated to 620 ft-lbs, if I recall right.

five7kid

iTrader: (14)

TGO Probuilt also has a good TH700R-4 reputation.

The one I'm running now was put together by a GM tech who does builds on the side. It already had a shift kit, he just did new frictions and replaced some heat damaged steels, it's been running fine for 3 years/race seasons.

kennn

FYI, I did some research on this topic recently. Apparently sometimes race cars have problems sealing head gaskets and blocks from coolant leak. The fix is to use an additive that seal off the coolant passages.

Maybe this is what you need, or you just need a new block?

I neither agree nor disagree. It depends on the application.

If you want to listen to your radio, use Dynamat or headphones. If you want to talk to your passenger, use headsets. If you want gas mileage, leave the passenger at home, or buy a Toyota