C headed 403 Build
#1
C headed 403 Build
4.380 Bore Custom Racetec piston, 1.5mm ring pack, 6cc valve reliefs. 9.5:1
Eagle LS 6.125 I beam rod
330 crank, ground to SBC Lg journal size, 3.400 stroke, internally balanced
5 main halo
C heads, 2.07/1.68 valves, just a cleanup and filled crossovers and welded dividers
Lunati Hyd roller 227/232@.050, .565/.565 lift 110lsa
RPM intake, center divider cut 1", opened ports to more closely match heads.
Holley Terminator TBI, 950cfm
Holley Dual sync
497hp/513tq.
Dyno sheet won't attach for some reason.
Eagle LS 6.125 I beam rod
330 crank, ground to SBC Lg journal size, 3.400 stroke, internally balanced
5 main halo
C heads, 2.07/1.68 valves, just a cleanup and filled crossovers and welded dividers
Lunati Hyd roller 227/232@.050, .565/.565 lift 110lsa
RPM intake, center divider cut 1", opened ports to more closely match heads.
Holley Terminator TBI, 950cfm
Holley Dual sync
497hp/513tq.
Dyno sheet won't attach for some reason.
Last edited by cutlassefi; November 12th, 2018 at 03:50 PM.
#5
#7
Joe, a guy makes a drop base (WFO is the name) for shaker 2nd gen TA's for use with the taller intakes but also if I am right the Olds 403 TA shaker base/top combo has an extension to get the scoop higher because the intake is flatter and lower than the stock 400 Pontiac shaker set up too so it might be Ok to use a stock Pontiac set up on it
#8
Joe, a guy makes a drop base (WFO is the name) for shaker 2nd gen TA's for use with the taller intakes but also if I am right the Olds 403 TA shaker base/top combo has an extension to get the scoop higher because the intake is flatter and lower than the stock 400 Pontiac shaker set up too so it might be Ok to use a stock Pontiac set up on it
#9
#10
Hello,
Mark built this motor to go in my ‘79 TA. I do plan to retain the shaker and once the motor is in the car, I will be able to determine which drop base to go with. Right now I am looking at either Blocker or PTFB. This is just a street car and Mark spec’ed it with that in mind. I have a 2004r built by Dan that will be behind it along with 3.42 gears.
Trey
Mark built this motor to go in my ‘79 TA. I do plan to retain the shaker and once the motor is in the car, I will be able to determine which drop base to go with. Right now I am looking at either Blocker or PTFB. This is just a street car and Mark spec’ed it with that in mind. I have a 2004r built by Dan that will be behind it along with 3.42 gears.
Trey
#11
Hello,
This is the motor that Mark put together for my ‘79 TA. Once it is in the car, I will be able to measure and figure out which way to go so that I can retain the shaker. Blocker and PTFB look like the top contenders for the drop base. This motor will be backed by a 2004r built by Dan ( Dr Dan) with 3.42 gears out back. (Second time trying to post with the pics)
Trey
#12
So a 410ci 403, cool. I am very impressed with your iron head build numbers lately, they put out way more than I expected. I am curious on why you went 1.5mm vs 1mm rings especially since they are custom. Not a criticism, just curious. Excellent build as per usual, your stoker small block builds have inspired me to finally at least get my 424 shortblock together come spring, so expect to hear from me in the coming months.
#13
Real simple on the ring choice, I always like to go as this as possible but this was the ring pack most readily available for this bore size.
And as far as output goes, I always like to double check my work. This had a Holley EFI on it which is a lbs/hr based system (not the best but it is what it is). The measured hp was about 462, (corrected was 497) and it showed 238# of fuel per hour in the Holley software. Based on a bsfc of about .52 that works out to be pretty damn close so I’m good with these numbers.
Let me know if can be of help in any way. Thanks Christian.
And as far as output goes, I always like to double check my work. This had a Holley EFI on it which is a lbs/hr based system (not the best but it is what it is). The measured hp was about 462, (corrected was 497) and it showed 238# of fuel per hour in the Holley software. Based on a bsfc of about .52 that works out to be pretty damn close so I’m good with these numbers.
Let me know if can be of help in any way. Thanks Christian.
Last edited by cutlassefi; November 14th, 2018 at 09:35 AM.
#14
Hello,
This is a motor for my 79 TA. Mark built it for drivability with a little attitude. As far as the shaker, I am looking at Blocker and PTFB as options for the drop base. I will know more once the motor and transmission (2004r) that Dr Dan built get back to Texas and we install them in the car. I am having the same issues of posting pics.
Trey
This is a motor for my 79 TA. Mark built it for drivability with a little attitude. As far as the shaker, I am looking at Blocker and PTFB as options for the drop base. I will know more once the motor and transmission (2004r) that Dr Dan built get back to Texas and we install them in the car. I am having the same issues of posting pics.
Trey
#23
Nice build and Mark told me about it. Where in Texas? We are in Round Rock/Georgetown.
To get your shaker to work - WFO-1 and a Pontiac Shaker base from Firebird central is what I am planning to try. We are using a Holley dominator. We have one 403 and one 424 for two of our cars and a third motor on deck.
I asked Mark to whack .25 off of an RPM for me as hood clearance on the RPM is a concern for what I am doing. I am not sure if it will work or not but I’ve seen the WFO rivets drilled out to center on the 403 motor using a Pontiac 400 shaker base.
Nice motor and glad to see another Olds in a Trans Am. We in fact paint ours Pontiac light blue just to confuse the lookers
To get your shaker to work - WFO-1 and a Pontiac Shaker base from Firebird central is what I am planning to try. We are using a Holley dominator. We have one 403 and one 424 for two of our cars and a third motor on deck.
I asked Mark to whack .25 off of an RPM for me as hood clearance on the RPM is a concern for what I am doing. I am not sure if it will work or not but I’ve seen the WFO rivets drilled out to center on the 403 motor using a Pontiac 400 shaker base.
Nice motor and glad to see another Olds in a Trans Am. We in fact paint ours Pontiac light blue just to confuse the lookers
#24
I am outside of Fort Worth.
I have contacted Blocker, and they stated they could make a drop base for me, they just want me to make some measurements first. PTFB stated that their dropbase might work by drilling the rivets and using and using the Pontiac shaker base (exactly like you described the WFO dropbase).
Mark did talk about taking .25” off the RPM, but I’m not sure if he did.
I have contacted Blocker, and they stated they could make a drop base for me, they just want me to make some measurements first. PTFB stated that their dropbase might work by drilling the rivets and using and using the Pontiac shaker base (exactly like you described the WFO dropbase).
Mark did talk about taking .25” off the RPM, but I’m not sure if he did.
Nice build and Mark told me about it. Where in Texas? We are in Round Rock/Georgetown.
To get your shaker to work - WFO-1 and a Pontiac Shaker base from Firebird central is what I am planning to try. We are using a Holley dominator. We have one 403 and one 424 for two of our cars and a third motor on deck.
I asked Mark to whack .25 off of an RPM for me as hood clearance on the RPM is a concern for what I am doing. I am not sure if it will work or not but I’ve seen the WFO rivets drilled out to center on the 403 motor using a Pontiac 400 shaker base.
Nice motor and glad to see another Olds in a Trans Am. We in fact paint ours Pontiac light blue just to confuse the lookers
To get your shaker to work - WFO-1 and a Pontiac Shaker base from Firebird central is what I am planning to try. We are using a Holley dominator. We have one 403 and one 424 for two of our cars and a third motor on deck.
I asked Mark to whack .25 off of an RPM for me as hood clearance on the RPM is a concern for what I am doing. I am not sure if it will work or not but I’ve seen the WFO rivets drilled out to center on the 403 motor using a Pontiac 400 shaker base.
Nice motor and glad to see another Olds in a Trans Am. We in fact paint ours Pontiac light blue just to confuse the lookers
#26
There is extremely limited hood clearance on a 70’s Trans Am. I wacked .375 off my dominator just not to have any issues that can’t resolve. What I like to do is compensate with gaskets or spacers in order to keep the shaker hood functional.
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