Recommendations for mopar 383 ss

Moparteacher · 12-03-2007, 06:07 PM

Hello all. After several years of on-again/off-again with my 69RR project it's on-again. I was up in the air as to whether it would be a stock or SS car. I've decided to go SS. The 69 383 combo for stock has too many hurdles with valve-to-piston clearance being the biggest issue.

I've spoken with several members in person over the last few years every Spring and Fall in Vegas, and all have been helpful. Thank You.

I have a few questions concerning pistons and appreciate any advice.

#1 Preference for piston manufacturer? I've already selected the C&A rod.
#2 Is the .990 pin legal for the 383? It is my understanding that many 440's run the .990 pin.
#3 Is it a requirement (legal) to lower the compression height to accommodate the increase in compression ratio with bore oversize, or can I run the stated compression height in the blueprint specs reguardless of bore size and the resulting compression ratio?
#4 Can I reduce the combustion chamber size the equivalent amount, or fewer cc's, of my valve notches? Example: Specs say cylinder head combustion size to be 79.5. Piston is flat top with 6cc notches, can the combustion chamber be reduced to 73.5cc's, and stay legal?

This vehicle, and myself, represent an educational institute. The ethics of legality are a high priority. Staying legal is a must, as I'm sure it is for all that contribute. Thanks for the advice. I'm looking forward to spending some time on the track in 08'.

Gary Weaver
College of Southern Nevada

div 5 · 12-03-2007, 09:13 PM

#3. run the blueprint compression ht. You can change the deck height as long as the gasket and deck height add up the same as bluepring specs. it is my understanding that if the piston is below the deck then it must stay there. same for above the deck.
#4 no.

Chuck Norton · 12-03-2007, 11:21 PM

1. Use the pin dimension as listed on the NHRA sheet. Whatever it says is the operative spec.
2. Use the compression height for your application as listed.
3. Use the combustion chamber volume spec as listed. Don't factor in valve notches. It is what it is.

Div 5's information on deck height is the way it was a few years ago. The current rule allows moving the piston/deck height to accommodate the available gasket. If you have to push the piston out of the hole a few thousandths to make up for the fact that the only gasket available is too thick, it will pass.

Paul Precht · 12-04-2007, 01:53 AM

79.5 cc is the min for 69.The AVS flows about 630 CFM Give me a call if you need more info, 570 735 3895 Eves EST, Paul.

bsa633 · 12-04-2007, 02:25 AM

any pin is ok in SS and the .990 pin is the most common in use but there seem not to be any legal aftermarket rod ava. with that pin bore,but you can ofcourse bush the oem rod,not sure how they feel about bushing down an aftermarket rod that has the specs shown already? have you seen the other thread that should be interesting for you?
http://classracer.com/classforum/showthread.php?t=8181

Jeff Lee · 12-06-2007, 01:02 PM

You are not restricted in SS on pin size. If the approved rod has a larger small end than you would like, re-bush the rod to your specifications. Note you may also use rod and crank spacer bearings in SS.

bob d · 12-13-2007, 01:42 PM

Call The "Westley Wocket" Don Little hes got 70 challeger rans 9 s in boise. its a 383.

SS/JA 9.97 132.62 05/15/06 Don Little - Westley, CA
'70 Dodge Challenger Eagle, ID

12-04-2007, 02:25 AM	#5
bsa633 Banned Join Date: Mar 2002 Posts: 310 Likes: 0 Liked 0 Times in 0 Posts	Re: Recommendations for mopar 383 ss any pin is ok in SS and the .990 pin is the most common in use but there seem not to be any legal aftermarket rod ava. with that pin bore,but you can ofcourse bush the oem rod,not sure how they feel about bushing down an aftermarket rod that has the specs shown already? have you seen the other thread that should be interesting for you? http://classracer.com/classforum/showthread.php?t=8181 Last edited by bsa633; 12-04-2007 at 02:28 AM.

12-06-2007, 01:02 PM	#6
Jeff Lee VIP Member Join Date: Jul 2007 Location: Anthem, Arizona Posts: 2,766 Likes: 0 Liked 3 Times in 3 Posts	Re: Recommendations for mopar 383 ss You are not restricted in SS on pin size. If the approved rod has a larger small end than you would like, re-bush the rod to your specifications. Note you may also use rod and crank spacer bearings in SS. __________________ Jeff Lee 7494 D/S '70 AMX

12-13-2007, 01:42 PM	#7
bob d Junior Member Join Date: Dec 2007 Posts: 4 Likes: 0 Liked 0 Times in 0 Posts	Re: Recommendations for mopar 383 ss Call The "Westley Wocket" Don Little hes got 70 challeger rans 9 s in boise. its a 383. SS/JA 9.97 132.62 05/15/06 Don Little - Westley, CA '70 Dodge Challenger Eagle, ID Last edited by bob d; 12-13-2007 at 02:03 PM.

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12-03-2007, 06:07 PM	#1
Moparteacher Junior Member Join Date: Nov 2007 Location: Boise Posts: 49 Likes: 0 Liked 0 Times in 0 Posts	Recommendations for mopar 383 ss Hello all. After several years of on-again/off-again with my 69RR project it's on-again. I was up in the air as to whether it would be a stock or SS car. I've decided to go SS. The 69 383 combo for stock has too many hurdles with valve-to-piston clearance being the biggest issue. I've spoken with several members in person over the last few years every Spring and Fall in Vegas, and all have been helpful. Thank You. I have a few questions concerning pistons and appreciate any advice. #1 Preference for piston manufacturer? I've already selected the C&A rod. #2 Is the .990 pin legal for the 383? It is my understanding that many 440's run the .990 pin. #3 Is it a requirement (legal) to lower the compression height to accommodate the increase in compression ratio with bore oversize, or can I run the stated compression height in the blueprint specs reguardless of bore size and the resulting compression ratio? #4 Can I reduce the combustion chamber size the equivalent amount, or fewer cc's, of my valve notches? Example: Specs say cylinder head combustion size to be 79.5. Piston is flat top with 6cc notches, can the combustion chamber be reduced to 73.5cc's, and stay legal? This vehicle, and myself, represent an educational institute. The ethics of legality are a high priority. Staying legal is a must, as I'm sure it is for all that contribute. Thanks for the advice. I'm looking forward to spending some time on the track in 08'. Gary Weaver College of Southern Nevada

12-03-2007, 09:13 PM	#2
div 5 Junior Member Join Date: Aug 2004 Posts: 13 Likes: 0 Liked 0 Times in 0 Posts	Re: Recommendations for mopar 383 ss #3. run the blueprint compression ht. You can change the deck height as long as the gasket and deck height add up the same as bluepring specs. it is my understanding that if the piston is below the deck then it must stay there. same for above the deck. #4 no.

12-03-2007, 11:21 PM	#3
Chuck Norton Member Join Date: Dec 2001 Location: Covina, CA Posts: 473 Likes: 104 Liked 81 Times in 18 Posts	Re: Recommendations for mopar 383 ss 1. Use the pin dimension as listed on the NHRA sheet. Whatever it says is the operative spec. 2. Use the compression height for your application as listed. 3. Use the combustion chamber volume spec as listed. Don't factor in valve notches. It is what it is. Div 5's information on deck height is the way it was a few years ago. The current rule allows moving the piston/deck height to accommodate the available gasket. If you have to push the piston out of the hole a few thousandths to make up for the fact that the only gasket available is too thick, it will pass.

12-04-2007, 01:53 AM	#4
Paul Precht Senior Member Join Date: Dec 2001 Location: Elysburg, Pa Posts: 730 Likes: 353 Liked 309 Times in 118 Posts	Re: Recommendations for mopar 383 ss 79.5 cc is the min for 69.The AVS flows about 630 CFM Give me a call if you need more info, 570 735 3895 Eves EST, Paul.