Free 383 for Blaze

[74Blaze]

@bucket

t And that's the crate 350 head? If you still don't want to try running the double humps and you don't have the budget for aftermarket heads, pretty much any large chamber smogger head will be a comparable replacement. They are a trash head to most people and will be practically free.

Yep, the Crate 350 Head. Don't want 11+:1 Compression, so I'm not using the Double Humps. I increased the budget and ordered the Summit SUM-152123 Heads. They are on sale right now for $499.99 each. By my calculation, I'll end up with about 10.2:1 compression. Probably the right decision. Sometimes I just end-up spending more money than I wanted to.

A closer look at my pictures shows that the Head Gasket was damaged in that area as well. Don't know which came first, the cracked Head or the damaged Gasket.

You must be registered for see images attach

 

[legopnuematic]

Those Summit heads are what I have on my 76. They were $350/ea back in 2019. If you didn’t know, they are Dart Iron Eagle heads.

Been in the truck since 2019 and 30k miles. No issues.

 

[74Blaze]

@legopnuematic

Good to know, Thank you.

I plan on using the 600 CFM Edelbrock 1406 Carburetor that has been on the Blazer for years. So the next question is what Intake Manifold should I use.

Options:
1) Use the original 1974 Blazer Intake (Pictured on top below)
2) Use the 1970 350 Intake that has been sitting around in my garage for years (Picture on the bottom below, needs reconditioning)
3) Dip further into our emergency savings and buy an aftermarket aluminum Intake. If so which one should I get?

You must be registered for see images attach

 

[xm20k]

If your carb will work and you don't mind cleaning up the stock manifold go for it but if you're looking for a bit of an upgrade the best deal for a universal (fits both old GM and vortec pattern) air gap style intake is about $200

Pardon Our Interruption

 

[74Blaze]

If your carb will work and you don't mind cleaning up the stock manifold go for it but if you're looking for a bit of an upgrade the best deal for a universal (fits both old GM and vortec pattern) air gap style intake is about $200

Thanks @xm29k

I've decided to use the old Intake. I'm having it sandblasted and the Gasket Surfaces freshened-up. It was originally the stock Intake that came on my long gone 1970 Monte Carlo which had the 300HP 350. That engine dropped a valve back around the turn of the century when it was in my '79 C10.

Working on cleaning and painting parts that will be used...

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

 

[74Blaze]

The intake cleaned-up nice...

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

 

[74Blaze]

I learned something new. Went to assemble the Timing Gear and discovered a bolt circle mis-match. After a call to Comp Cams, it turns out that the Roller Cam requires a Camshaft Retaining Plate making the smaller bolt circle necessary. the 383 has the 1995-2000 Engine Block, so it was just a matter of purchasing the Camshaft Retaining Plate and the correct Timing set. More money into the "Free 383" project.

You must be registered for see images attach

You must be registered for see images attach

 

[bucket]

I learned something new. Went to assemble the Timing Gear and discovered a bolt circle mis-match. After a call to Comp Cams, it turns out that the Roller Cam requires a Camshaft Retaining Plate making the smaller bolt circle necessary. the 383 has the 1995-2000 Engine Block, so it was just a matter of purchasing the Camshaft Retaining Plate and the correct Timing set. More money into the "Free 383" project.

You must be registered for see images attach

You must be registered for see images attach

More correctly, it's not because of it being a roller cam. It's because the cam is designed as a replacement for a factory-installed ('87+) roller cam. A standard aftermarket roller cam that requires a cam button would use a cam sprocket with the regular bolt pattern.

 

[74Blaze]

Next issue. I have a slight interference that I traced down to a few of the Connecting Rods contacting the Cam Lobes in certain crank positions. I need to have the tops of the Rod Cap Screw Bosses chamfered to eliminate the contact. The area that I marked in Red in the picture below is where the chamfer needs to be. Anyone know of a good engine machine shop in the Southern Indiana area? Anywhere from Indianapolis to Louisville, KY would be OK

You must be registered for see images attach

 

[74Blaze]

Found my Connecting rods on the Eagle Specialties site. Sometime between when Roach bought them and now they added chamfers where I need them. Oh well, I found a shop in Indy that is going to fix mine so they won't interfere with the Cam Lobes.

You must be registered for see images attach

 

[ChuckN]

Found my Connecting rods on the Eagle Specialties site. Sometime between when Roach bought them and now they added chamfers where I need them. Oh well, I found a shop in Indy that is going to fix mine so they won't interfere with the Cam Lobes.

You must be registered for see images attach

Might be cheaper depending on how much the machining is, to get a small base circle cam. Many companies offer them off the shelf. Just food for thought.

 

[ChuckN]

Ah, never mind, they’re more expensive than I remembered in mid-500s.

 

[Craig Nedrow]

man, just grind them yourself, however if this has geen prevously balanced, they will need to be rebalanced. Weigh them before and after to see how much was taken off. Wish I was close, could put them in the mill and be done in an hour.

 

[74Blaze]

@Craig Nedrow @ChuckN
Yeah, Roach, the original builder had it balanced. Sh!t, the engine was ready to drop in if I wanted a high-RPM race motor. The machinist in Indy will make it right. Just cost more time and money. But the goal is to have a strong running engine in the Blazer by next Spring. I don't drive it from the time the salt the roads until the Spring rains have washed them all clean. So, I'm more interested in having it right then rushing to get it done.

 

[JBswth]

Yep. That's what I was afraid of. They guy used the '55 as a street racer back in the 80s & 90s. I'll need to figure out what Cam I want in it for my trail rig. I don't mind the 11:1 compression as I'm thinking that it should run fine on 91-93 octane with the right Cam. No need to worry about the stall speed as I'm running an SM465 manual.

No it won't run fine on pump gas with 11:1 compression. It might not ping under load at normal speeds, but it may very well ping at the high RPM that cam is intended for, and high RPM pinging can knock holes in your pistons. You need a torque cam and much lower compression.

J. B.