'75 sbc

[72malibu]

It's getting buttoned up and headed to the dyno for break in shortly. Original motor owned by my dad since '76. It's a 350 bored .060 with a mild hydraulic roller cam, port matched GM 882 heads, dual plane Edelbrock, Holley 650, HEI, and headers. A little sportier than factory but nothing crazy. 8.5:1 to 9:1 compression so it'll run on 89.

Who doesn't like pictures?

[Ziegelsteinfaust]

That looks like it will be a good engine for you.

Did you do anything else to the 882 heads? They respond well to back cut valves, and a little bowl blending.

Good job on going with a roller cam.

On 9-1 I almost always got away with running 87 octane.

[72malibu]

That's a good question. I'll have to ask the builder. He runs a machine shop but stopped building motors for customers years ago and did this one as a favor because he was friends with my brother who passed. It's going into a Gentleman Jim.

Yes, I won't use anything but a roller cam anymore. This one is an Erson and took several months to get due to supply chain issues.

I'm running a mild Mike Jones hydraulic roller in my 400 sbc 72 Chevelle and the valvetrain is quiet as can be. Here's that one.

[geezer#99]

There you go
A nice little 250 horse 350!

[Willowrun]

Interested in your build specs for your 400. I have a stock bore '79 400 I pulled from a running k5 years ago I'd really like to build so interested in how you built yours.

[72malibu]

The 400 came with the car as .030 with Dart Pro 1 200 cc heads, 6" rods, a Comp Cams XR276HR-10, and the Victor Jr. The wrong fuel pump pushrod was installed (no bronze tip) and it ate the lobe.

When I had it rebuilt, I reused as much as I could to save money. Otherwise, I'd have at least switched to a dual plane intake. It went to .040 with the same heads, intake, etc. The Jones cam is mild and produces about 15" vacuum at idle. It's good enough for me in front of a Richmond 5 speed with a 3.26 first gear and 2.73 posi. I can cruise all day at 75 mph.

272/276 @.006"
224/228 @.050"
.340"/.340" Lobe Lift
.510"/.510" Valve Lift w/1.5 rockers
112 LSA

[mattfranklin]

Sounds like a nice little motor.

[Tom]

Originally Posted by geezer#99

There you go
A nice little 250 horse 350!

A stock goodwrench 350 will do more on a dyno. With headers this sounds more like 300 ponys to me.

[vince1]

Either way 250 or 300 hp, that is a lot more than the stock 165 HP rating of the 79 350 in my truck. Maybe a different cam bumped it up a bit more. It is still ample power though for what I use it for and so much better than the six it replaced.

[72malibu]

Yeah, the '75 sbc 350 - 4 barrel had only 160 net hp, so this should be a major improvement regardless.

If we get the motor on a dyno I'll post the results with cam specs.

[GSP7]

how many miles on the short block?

[Tom]

Originally Posted by 72malibu

Yeah, the '75 sbc 350 - 4 barrel had only 160 net hp, so this should be a major improvement regardless.

If we get the motor on a dyno I'll post the results with cam specs.

Comparing published numbers over the years can be tricky.
A goodwrench 350 is exactly the same as a 75 350: 76cc poor flowing heads, 8.5:1 compression, 350cid, worlds tinest cam. Its rated 260HP w/headers.

[geezer#99]

I seem to have guesstimated a bit high.
Closer to 220 hp.

[72malibu]

Originally Posted by GSP7

how many miles on the short block?

Good question. My dad ran a 396 in the truck for a while so it would be something less than whatever the ODO says. But I imagine it's over 100k miles because he drove it daily/regularly until the 2000s. Well seasoned.

[72malibu]

The 350 was run on a dyno to break it in and all went well. No "pulls" were made -- it was just run for an hour. Guesstimate by the dyno guy is 300 hp, FWIW.

[72malibu]

I got the cam specs for this 350, in case anybody is interested.

It's an Erson hydraulic roller
272/272
.480/.480
218/218 @ .050
.320/.320 @ .050
with 1.5 rockers
110 LSA