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I'm looking for reference on a person/shop San Antonio and South who does Olds engine work.
I've read a bit on Precision Engine in Houston, but haven't seen reviews, and they are 5.5 hours north of me.
I'm looking for a rebuild/replace on my 307 LG8 with 7A heads, porting, cam... to pull 240HP/280TQ. Not interested with a 350 or other swap, I'm keeping this "original" as its a 7.5-8/10 59K original.
Last edited by 86 Olds 442; October 21st, 2020 at 11:21 AM.
I am very interested in the outcome of this build. No one bothers with a 307, especially a 7A headed motor. I assume you are planning on keeping the stock exhaust? The crossover pipe and cat are a huge restriction. Maybe a custom larger crossover pipe and high flow cat might help. Olds gained 30 hp with ram air shorty headers, y pipe and Corvette cat on your motor in the FE3X prototype. Good luck, sounds like you have some good choices for builders. VP, you think 455 heads flow poorly, wait till you see heads that flow 135/120 cfm.
I will definetly post what the outcome is, be it good or marginal. Once the motor is done, a high-flo cat will be added. I'd prefer to keep the pipes stock as well.
Thinking of using chevy 7.7 rods vs. the Oldds 7.717 ... reason for this is a Comp 262HR cam has .505 lift, but with the shorter rod and 1.6 rocker this should ease up on the springs and give a .478 lift vs. the VIN 9 .437. This cam also should not be too wild as it adds 6 degrees in intake and 8 on exhaust at 0.050, while only adding 5 degrees of overlap and maintaining vacuum for street use.
This is what i have modeled as a cam compare for the 262 vs the original 9 cam
Last edited by 86 Olds 442; October 22nd, 2020 at 07:45 AM.
Reason: add cam compare
Awesome, then it will be a challenge. Yes, the 307 is raced. I think almost all of them use heavily modified 5A heads. Here is the comparison, the 5A heads have 155cc runners, the 7A, much smaller and the port can supposedly can't be raised a lot.http://tech.oldsgmail.com/307_heads.php
Here is a weird mix match from Oldspower. Someone stuck on a A4 and thankfully iron exhaust manifolds on a swirl port 307. Of course the owner wants a lumpy cam in a 8 to 1 compression, on a good day 307. You can really see the port difference as there is a early normal port Turkey Tray sitting on the 7A heads intake ports. Another thing to remember Oldsmobile left the same lean primary jetting, just allowed the secondaries to open all the way with richer secondary rods and hanger. The biggest issue is the nearly 60 degrees of timing the swirl port ECM put out. It will make cam timing and compression ratio key to this being fun to drive. I assume Premium fuel is fine and will be ran?
VortecPro - why Georgetown ? Moving ? Guess the secret is Out....
My brothers place is right by Texas Speed.....like next door.
I spent all day today there.
Last edited by olds403; October 23rd, 2020 at 09:00 PM.
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,719
Originally Posted by olds403
VortecPro - why Georgetown ? Moving ? Guess the secret is Out....
My brothers place is right by Texas Speed.....like next door.
I spent all day today there.
Very close to TS myself, walking distance. My 92 year old Mom lives there I need to take care of her.
October 21st, 2020, 08:33 AM
