help me out on this engine build

[tjgp360]

ARGH!!!!!! i just wrote this extremely long explination and it got deleted.....F*#K!!

to make a long story short i got a cast intake to go to 4bbl one mechanic trash talked the cast iron forced me to get a aluminum intake.....so i bought a 4bbl performer and went to another mechanic and he pointed out that the runners were too small and stated that i would lose power brakes and that i should get single plane for a street car....

so i will rebuild my own engine in spring

i have the opportunity to buy a early 340 intake and J heads (1.88,1.60)

i recently took a ride in a friends 2008 grand prix gxp and it PULLED lol i mean all the way up to 100

so keeping that in mind i want to be able to whoop it at stop light matches

so along with the intake and heads what else should i do to pick up performance

of course a camshaft but im not sure what to look for to keep a smooth idle

so is there anything i else i need? pistons?

 

[Cranky]

What motor, what car and what's your intended application? Street only with highway driving or a street/strip bruiser?

 

[72Satellite440]

The GTP does 13.885 stock -1/4 mile....depending what you drive he maybe tough to beat

 

[tjgp360]

sorry about not leaving the type of engine it was all in the original post that got deleted lol, anyway its a la block 360 in a 79 cordoba, im pretty sure i need to change my rear gears i think im running 2.76 gears, i was thinking to move up to 3.23 for the best of both worlds until i got in the gxp....geez he scared the hell out of me in that car, BUT that only because he was on a residential street @95mph...so now im thinking 3.55, i read that the gxp has 3.29 gears and that damn 5.2 ALUMINUM v8

 

[bbeep69]

I don't know where you found these mechanics but they are both way off-base.
Definitely DO NOT use a single plane intake. You will lose low end torque with a single plane and you need torque to get a big car like the Cordoba moving. Unless you really build that 360, and maybe stroke it up a good bit, you won't match the gxp's performance if that is what you are after.
To beat the GXP will take a lot of work for a 360 in a Cordoba. The cam you will need for this build will not provide a smooth idle, that is for sure. You'll need at least a 10:1 compression ratio which means new pistons, a cam with around 240 degrees or more of duration measured @ 0.50 valve lift, headers, roller rocker arms, a good bit of porting in the heads, a 750 cfm carb (Holley, Demon, Barry Grant), an Edelbrock Performer RPM Air Gap intake manifold, 3.91 - 4.10 gears and a Sure Grip, a 2800-3200 rpm stall converter and shift kit for the transmission along with heavy duty rear springs, some good, wide meats for the back end and a complete brake overhaul just to make sure you get the car stopped when you are beating on it. To make that Cordoba a GXP killer will take a lot of work.

 

[GTXKen]

To make that Cordoba a GXP killer will take a lot of work.

and a good deal of cash

 

[tjgp360]

Okay well let me rephrase wht I exactly want to do...a gxp killer would be awsome but in reality I want a good performer, honestly I dnt mind not being able to kill it but I do want to be able to run with the newer cars off the line. Now as for the cam selection I can live with a lumpy idle I actually like the sound but what is unnatractive is the loss of vacuum for my brakes and what not.... so with that being said what would be the best cam\head\gear ratio combo for the a mostly street\freeway with some track appearences and would going .030 really benefit me

 

[Meep-Meep]

Yep, you are in the hole already with a pretty heavy car. I would look up the GTP and see what it weighs and the HP / torque numbers it has and compare with your car. What's the 1/4 mile MPH of the GTP? With your heavy car you will need deep gears to get it moving if you don't have cubic inches to fall back on.

I agree that a single plane won't do you much good but don't agree with your mechanic about the iron intake. I ran 109 MPH in the 1/4 with an M1 dual plane, which is basically a copy of the factory iron 440 intake. You need an engine that produces the most average power for the intended purpose, which in this case sounds like 1/4 mile use.

 

[snakeoil24]

Sink the Cordoba in the ocean and get a Duster and put a 440 in it and go enjoy yourself.

 

[tjgp360]

ok now you guys have got me thinking......right now its my everyday driver and soon enough i will own a 98 durango.....im thinking of a 440 BUILD BABY!!!

but if i go that route i will build the 440 seprately then eventually drop it in, with the 440 it will still be a street car but if i make that move i will want to slaughter anything stock

so back to the 360 do you guys think i will be ok with just new gears, the cast iron intake, Heads (maybe) and a thermoquad

 

[73rr]

I just do not think that you will ever have a 'streetable' 360 that will push a Cordoba to mid 13's...
The easy comparison is to look at a 1500 Ram with the 5.7, similar weight and alot more grunt on tap.
You might start thinking about a 5.7 swap...they can make 500hp without alot of work.

just my 2¢

.

 

[Coronet 500]

Those 340 intake manifolds are good,go for the heads maybe with a cut to bump your compression.TQ's, love 'em or hate 'em, I like them for a cheap carb but like Holley better, with vacum for your car. If you dont care about gas mileage, go all in with a 3.91 if you have a 727, a 904 would be the weak link. Try looking at Comp Cams Camquest program for your stick. Don't have to buy from them but it's fun to fool with. If you cut the heads ask to have the intake side done too. May need different pushrods but they're not to expensive.

 

[Meep-Meep]

Just to shed some more light into this project and perhaps some encouragement, back in the 80's I watched an early 70's Imperial battle cruiser or some other BIG C body run a 13.90 at Fremont with a 440 six pack. I still remember the license plate. 1RADBOT.

 

[tjgp360]

okay the you say the 5.7 has more grunt than the 360(5.9) now is the differences in the block and overall engine design that just makes the 5.7 easier to make power?, because in my mind i keep think 360 = more cube which is more potential i just need the right parts to piece them all together

BUT if you say the 5.7 is better i will take your word after all im pretty new to the engine building game, so if i swap to a 5.7 will i be back to the gxp killer dream lol or will i be into reality performance

oh and i believe i have the 999 trans its a stock floor shift with what seems like a shift kit , but what do you mean with a "cut" for compression. honestly depending on prices right now i might go with coronets advice and save money for a 440 build, but after im done im not sure if its going in the doba or the durango LOL

 

[Coronet 500]

By cut I mean milling the head or to plane the head. If they are open chamber milling off .0048" equals a reduction of 1cc of chamber volume. I've heard maximum removed can be .060", I wouldn't go more than .050". For every .010" removed from the head, .0095" should be removed from the intake face to maintain proper width between heads when on the block for proper manifold fit.

 

[73rr]

The big question you need to ask yourself is how deep are your pockets??

In todays market you can approach horsepower/torque from different directions.
As good as the LA engines are, it will still cost more to make 'x' amount of power than if you start with a B or RB. For a fairly heavy car you need lots of torque, and big stokes not only make inches they make torque.
Example; a 4.0" forged Eagle crank, for the 360, sells for about $600 OR a 4.5" forged crank for a 440 sells for about $700 and you get over 500 cubic inches instead of the 400 from a small block. You can even do it cheaper if you install a 440 crank in a 400 block for a 450 inch package.
Custom rods and pistons are needed for custom cranks but the 440-400 package can use either the 400 or 440 rod and pistons are on the shelf.
With either package you can use stock intakes and heads or you can buy the good aftermarket pieces but there is little difference between small block and big block prices.
You can even build a 'killer' 500 hp 440 without a big crank, it would just be a different pile of parts.

The 'other' route to consider is to swap in a 5.7 with all of the electronics and play with the computer to make power. Remember that the SRT8 6.1 is rated at 425 hp and it is far from radical. If you are not compooooter savvy then this may not be the best way to go. Read through some of the swap projects here and on the A body side for insight.

If all of this is new to you then my suggestion, for the best bang for the buck, would be to start with a stock(ish) 440 and see how lots of torque feels. There are still plenty of 440's floating around, check craigslist. I just bought a 400 for $150 and a 67,000 mile 440 with trans for $450!

Gary

 

[74sundance]

See an engine builder not a Mechanic. I've done both jobs. A mechanic knows a little about lots of cars and other things but an engine builder knows engines (Period). Don't get me wrong some mechanics do know engines but most don't do performance work they do repair work.

 

[tjgp360]

this is really overwhelming lol well I was looking into the 400 blocks and I came across a 07 RAM hemi that needs a rebuild (oil pump went out) for $500 obo
So what do you guys think? I figure I can grab this then stroke it to 6.7 (410) or a 6.4

Or do you guys think I should make the 360 a 408 stroker?

 

[72Satellite440]

I vote stroker 360-

 

[Coronet 500]

Boy, gone a long way from a set of heads. I vote 408, proven engine, drop right in, best bang for your buck.