1969 L78 396 375 HP Dyno Test

[bbbentley]

Long Live L78's! The unsung hero and road warrior of the Big Block Kingdom.

[Rixls6]

Nice numbers on that L78. [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img]
I have a similar build that is nearly done, although it is .070 over, with a bit more aggressive cam.
I hope to make a little more power, but the dyno will tell.

[Postsedan]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bbbentley</div><div class="ubbcode-body">Long Live L78's! The unsung hero and road warrior of the Big Block Kingdom. </div></div>

You`re my Unsung Hero [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img]

Dan

[Survivor 69/Z28]

So is it safe to say that these cars when new had this kind of HP with a set of headers bolted to them?
Very impressive!!
I had always heard that the 69 Z's were just as fast when geared properly.

[VintageMusclecar]

In as-delivered condition with manifolds, I'd say the factory 375 HP rating was fairly accurate. Headers are typically worth ~30 HP on these engines.

Read this and note what JRSully stated on the last page.

[Survivor 69/Z28]

Eric,
I may need to call you sometime about my stumbling issue on my 69 L78.

Love the stock look but with headers! They just make these old motors run so much better.

[cook_dw]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: L78racer</div><div class="ubbcode-body">Factory jetting? </div></div>

X2



Also what was the total timing?

Great numbers!

[L78steve]

My 70 L78 Nova with manifolds and stock exhaust with crossflow muffler is disappointing.
On the 67 L78 with headers and a Flowmaster system is like Mr Toads wild ride.

Headers worked well on this engine when they were open. Seemed like it would rev forever.

[JRSully]

L78s MUST have headers to get everything out of them, IMO. Timing all in by 3k. I have this set up in my Nova and it just screams and has stayed VERY reliable for the past bunch of years, only deviation from stock are roller rockers, no ported heads, no larger valves, orig 569 flattie intake, orig Holley 4557, orig cam, orig compression, bored 30 over. do have a Pypes exhaust system with transverse muffler mounted in stock location. I think dyno'd at about 425 @ 5700, right about where it should be